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1918 


A.  C.  ABBOTT,   M.D. 


Digitized  by  tine  Internet  Archive 

in  2010  with  funding  from 

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http://www.archive.org/details/hygieneoftransmiOOabbo 


THE  HYGIENE 


OF 


Transmissible  Diseases: 


Their  Causation,  Modes  of   Dissemination, 
and  Methods  of  Prevention, 


BY 

A.  C.  ABBOTT,  M.  D., 

Professor  of  Hygiene  and  Bacteriology,  and  Director  of  the  Laboratory 
of  Hygiene,  University  of  Pennsylvania. 


ILLUSTRATED. 


PHILADELPHIA: 
W.    B.    SAUNDERS, 

925  Walnut  Street. 
1899. 


COPVRIGHT,   iSgg, 
By  W.   B.   SAUNDERS. 


CLECTROTVPED  BY  PRESS  OF 

WE9TC0TT   a.  THOMSON.    PHILA.  W.    B.    SAUNDERS.    PHILA 


PREFACE. 


The  contents  of  this  book  are  essentially  the  subject-mat- 
ter of  a  portion  of  my  lectures  on  General  Hygiene  at  the 
University  of  Pennsylvania. 

It  is  not  the  purpose  of  this  work  to  present  the  subject 
of  Hygiene  in  the  comprehensive  sense  ordinarily  implied  by 
the  word,  but  rather  to  deal  directly  with  but  a  section,  cer- 
tainly not  the  least  important,  of  the  subject — viz.,  that  em- 
bracing a  knowledge  of  the  preventable  specific  diseases. 
Incidentally,  as  occasion  may  require,  there  are  discussed 
those  numerous  and  various  factors  that  have  not  only  a 
direct  bearing  upon  the  incidence  and  suppression  of  such 
diseases,  but  that  are  of  general  sanitary  importance  as 
well. 

In  the  preparation  of  this  work  only  the  most  trust- 
worthy authors  have  been  consulted,  and  only  those  pre- 
cepts embodied  that  are  now  generally  accepted  by  sani- 
tarians as  sound. 

It  will  be  manifest  to  the  reader  that  a  great  deal  is  still 
wanting  to  complete  our  knowledge  upon  many  important 
phases  of  the  subject,  and  no  effort  has  been  made  to  dis- 
guise this  fact. 

The  frequency  with  which  requests  are  received  for  infor- 
mation concerning  the  detailed  management  of  transmissible 
diseases  is  in  part  the  reason  for  the  publication  of  this  book. 

I  trust  the  work  may  serve  a  useful  purpose. 

A.  C.  A. 


CONTENTS 


PAGE 

Introduction 17 

Causation  of  Disease , 25 

Predisposing  Causes 26 

Age 27 

Sex 29 

Race 31 

Occupation      37 

Density  of  Population 41 

Heredity 45 

Season 47 

Exciting  Causes 50 

Chemical   Causes 52 

Physical  and   Mechanical   Causes 53 

Animal   Parasites 53 

Bacteria       .    .    . 54 

The   Causation,    Modes    of   Dissemination,   and    Prevention   of 

Special  Diseases 63 

Typhoid  Fever 63 

Asiatic  Cholera 89 

Amoebic  Dysentery 97 

Tuberculosis 100 

Acute  Croupous   Pneumonia , 107 

Diphtheria Ill 

Epidemic  Cerebrospinal   Fever 118 

Influenza 124 

Bubonic  Plague 126 

Suppurative  and  Septic  Infections 133 

Venereal   Diseases 140 

Leprosy 14S 

Tetanus  (Lock-jaw) 155 

Anthrax 160 

Glanders 166 

Actinomycosis ■ 17^ 

Madura  Foot 174 

Small-pox • 176 

Varicella    (Chicken-pox) 180 

Measles 181 

15 


1 6  CONTENTS. 

PAGE 

Scarlet   Fever 1 82 

Whooping  Cough 186 

Mumps 188 

Malarial   Fever 189 

Yellow  Fever 202 

Dengue 208 

Typhus   Fever 211 

Relapsing  Fever 214 

Rabies  (Hydrophobia)  . 216 

Diseases  due  to  Animal  Parasites 223 

Prophylaxis  in  General  against  Infectious  Diseases: 

Vital  Processes  : 

Immunity ;  Vaccination   and   Protective    Inoculation ;    Antitoxic 

Condition 241 

Chemical  and  Physical  Prophylactic  Measures 259 

Disinfection  and  Disinfectants 259 

Special  Chemical  Disinfection 277 

Privy  Vaults,  Evacuations,  etc 277 

Water-closets,    Urinals,  and  Sinks 278 

Stables  and    Cellars 279 

Wells  and  Cisterns 280 

Disinfection  of  the  Hands 281 

Disinfection  through  Physical  Processes 282 

Disinfection  by  Heat 282 

Steam 283 

Desiccation 288 

Sunlight 288 

Electricity .' 289 

Mechanical  Agitation    . 290 

Important   Precautions  in  the    Management   of   Communicable 

Diseases 291 

Isolation 291 

The   Sick-room .  292 

Clothing 294 

Excreta 295 

Room  Disinfection 296 

Care  of  the   IJody  after   Death 298 

Quarantine 299 

INL-EX ♦ 305 


The  Hygiene 


OF 


Transmissible  Diseases. 


INTRODUCTION. 

Hygiene  is  the  science  that  deals  with  the  laws  of  health, 
in  the  broadest  sense. 

Practical  hygiene,  or  sanitary  science,  is  the  art  of  pre- 
serving health  (or  of  preventing  disease),  and  includes  a  con- 
sideration of  the  methods  that  are  employed  in  investigating 
the  manifold  phases  of  the  subject. 

It  is  obvious  that  the  fundamental  points  to  be  considered 
in  the  study  of  hygiene  are  those  bearing  upon  the  conditions 
under  which  we  live.  Hygiene  is  not  so  much  a  study  of 
man  as  a  study  of  man's  surroundings,  with  the  view  of 
determining  in  how  far  these  are  conducive  or  detrimental 
to  his  well-being. 

Among  the  earliest  medical  and  ecclesiastical  writings  are 
encountered  laws  for  the  sanitary  guidance  of  man.  It  is  due 
largely  to  the  inculcation  of  these  precepts,  handed  down 
from  generation  to  generation,  that  we  follow  particular 
modes  of  living  and  still  instinctively  avoid  certain  condi- 
tions then  thought  to  be  harmful.  Probably  the  most 
familiar  of  the  early  writings  on  the  subject  are  the  laws  of 
Moses  for  the  guidance  of  his  people.  Since  practically 
nothing  was  then  known  as  to  the  direct  causation  of  disease, 
these  laws  were  of  necessity  empirical,  though  the  measures 
recommended  for  preventing  the  spread  of  contagion,  for 
cleanliness,  for  the  killing  of  animals  for  food,  for  the  isola- 
tion of  infectious  maladies,  and  for  the  renovation  of  dwell- 
2  17 


1 8  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

ings  inhabited  by  contagious  diseases  are  alone  sufficient  to 
warrant  the  belief  that  they  were  formulated  from  close 
observation  and  trustworthy  experience. 

The  older  writings  on  hygiene,  and  in  fact  many  of  those 
of  comparatively  modern  date,  were  in  the  main  speculative, 
representing  the  dictates  of  instinct  and  intuition.  They 
were,  nevertheless,  of  undoubted  benefit  to  those  Avho  heeded 
them  and,  in  so  far  at  least  as  the  Jews  are  concerned,  were 
unquestionably  instruments  in  repeatedly  shielding  them  from 
the  rax-ages  of  pestilence. 

That  the  importance  of  personal  and  municipal  hygiene 
was  fully  appreciated  by  the  earlier  civilizations  generally, 
there  is  abundant  evidence.  The  question  of  public  health 
was  one  of  vital  importance,  and  their  desire  and  ability  to 
carry  their  precepts  into  practice  have  been  abundantly  dis- 
covered through  the  researches  of  the  archeologist.  In 
many  instances  their  devices  for  baths,  water-supplies,  dis- 
posal of  sewage,  and  for  light  and  air  left  little  to  be  desired. 

With  the  progress  of  time,  the  growth  of  communities,  and 
the  demands  of  modern  life,  it  became  evident  that  the  earlier 
sanitar}^  codes  must  be  recast  to  meet  the  requirements  of 
newer  conditions.  The  older  regulations  were  based,  as  has 
been  said,  in  many  important  particulars,  upon  speculation 
and  erroneous  conceptions  ;  though  it  must  be  admitted  that 
they  erred  more  frequently  on  the  right  than  on  the  wrong 
side. 

About  the  middle  of  the  present  century  it  was  realized  by 
tho.se  who  have  done  most  to  place  hygiene  on  a  sound  basis 
that,  through  the  application  of  methods  of  precision  to  the 
study  of  man  and  his  surroundings,  much  light  could  be 
thrown  upon  many  phases  of  the  problem  that  had  hitherto 
been  but  imperfectly  understood.  In  consequence,  through 
the  utilization  of  chemical,  physical,  histological,  stati.stical, 
and  bacteriological  methods,  the  empirical  hygiene  of  the 
past  has  in  part  given  place  to  the  more  exact  hygiene  of 
to-day.  In  the  light  shed  by  such  trustworthy  methods  of 
analysis  we  are  in  a  favorable  position  to  interpret  and  appre- 
ciate the  me^uiing,  the  value,  and  the  wisdom  of  many  of  the 


INTRODUCTION.  1 9 

laws  and  customs  that  were  in  vogue  in  earlier  times  for  the 
regulation  of  health  and  disease. 

The  foundation  of  modern  hygiene  is  laid  in  the  scientific 
investigations  of  von  Pettenkofer  on  ventilation  and  heating, 
on  the  relation  of  soil-moisture  to  health,  on  the  physical 
properties  of  clothing ;  and  in  those  of  himself,  associated 
with  Voit,  on  the  chemistry  of  respiration  and  general  nutri- 
tion, and  the  chemico-physiological  values  of  food-stuffs  in 
the  process  of  alimentation ;  and  in  the  brilliant,  epoch- 
making  researches  of  Koch  upon  the  etiological  relation  of 
micro-organisms  to  disease.  With  the  impulse  given  to  the 
work  by  the  intelligent  deductions  of  these  pioneers  in  modern 
hygiene  there  was  a  development  in  our  knowledge  along  all 
the  manifold  ramifications  of  the  subject,  and  to-day  the  field 
of  hygiene  has  assumed  such  vast  proportions  that  only  a 
rare  intellect  can  master  in  detail  its  numerous  phases. 
Indeed  the  subject  is  already  divided  into  its  specialties,  and 
complete  works  on  hygiene  are  no  longer  attempted  by  single 
individuals,  but  are  rather  edited  as  systems  of  monographs, 
each  contributed  by  individuals  who  devote  their  time  exclu- 
sively to  the  study  of  this  or  that  particular  branch  of  the 
subject,  and  who,  therefore,  have  the  special  knowledge  neces- 
saiy  to  clear  and  complete  enunciation.  Not  only  has  the 
development  of  knowledge  upon  hygiene  alone  been  veiy 
conspicuous  but,  through  special  investigations  of  hygienic 
significance,  its  influence  has  been  widespread,  and  much 
light  has  been  thrown  upon  topics  of  general  medical 
interest. 

It  is  manifestly  inadmissible  longer  to  connect  the  teaching 
of  hygiene  with  that  of  any  other  branch  of  medicine.  It 
has  become  a  science  of  itself,  and  as  such  should  be  in  the 
hands  of  those  who  have  undergone  the  special  discipline  nec- 
essary to  appreciate  fully  the  nature  and  importance  of  the 
problems  involved.  The  time  is  past  for  the  student  to 
receive  adequate  instruction  in  this  work  from  the  "  Pro- 
fessor of  Obstetrics  and  Hygiene,"  of  "  Dermatology  and 
Hygiene,"  of  "  Materia  Medica  and  Hygiene."  as  has  been 
the  case  for  so  long  a  time  in  many  institutions  of  learning. 


20  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

The  times  demand  that  the  teacher  of  this  department  of 
work  be  one  who  has  been  systematically  trained  in  its 
various  departments,  not  of  necessity  to  the  extent  of  being 
master  of  each,  but  certainly  as  master  of  some,  and  in  gen- 
eral to  a  degree  that  will  enable  him  to  comprehend  and 
elucidate  fully  the  problems  that  present. 

W'h}'  should  a  physician  trained  to  cure  the  sick  equip 
himself  with  a  knowledge  that  he  is  to  employ  in  preventing 
sickness  ?  Why  should  a  physician  practise  preventive  med- 
icine and  follow  the  precepts  of  hygienic  teaching  ?  are  ques- 
tions that  are  occasionally  asked.  One  might  as  readily  ask, 
why  does  one  experience  the  impulse  to  rescue  from  danger 
a  stranger,  in  whom  he  has  no  direct  interest  ?  Laying  aside 
the  question  concerning  his  functions  as  a  physician,  there  is 
every  moral  reason  why  he  as  a  man  should  use  his  best 
endeavors  to  lessen  suffering  and  save  life,  in  so  far  as  it  lies 
in  his  power  to  do  so,  and  this  too  regardless  of  whether  it  is 
to  be  of  direct  profit  to  him  or  not. 

In  the  second  place,  there  are  material  reasons  for  a  phy- 
sician's having  a  fairly  accurate  knowledge  of  the  advances  in 
preventive  medicine.  His  patients  demand  it.  With  the  uni- 
versal progress  in  general  education  the  public  is  no  longer 
satisfied  that  a  physician  enter  the  house,  prescribe  his  medi- 
cines, and  depart ;  they  desire  more  :  they  wish  to  know  the 
nature,  the  origin,  and  the  cause  of  the  sickness,  the  most 
like!)'  channel  or  channels  through  which  the  disease  was 
contracted,  and  the  most  reliable  means  of  preventing  its 
recurrence  or  spread.  If  the  doctor  cannot  promptly  supply 
reasonable  answers  to  these  cjuestions,  he  need  not  be  sur- 
prised if  his  employment  be  given  to  someone  else  who  can. 

In  the  third  place,  for  his  own  enlightenment  and  personal 
welfare  the  physician  should  be  f^miiliar  with  sanitary  laws, 
especially  tho.se  concerning  the  causation  and  spread  of  dis- 
ease and  the  means  of  prevention.  He  should  be  familiar 
with  the  modes  of  infection,  the  methods  of  disinfection,  the 
means  for  the  isolation  of  the  sick,  and  the  general  rules  of 
prophylaxis  in  the  management  of  contagious  diseases.  He 
should  be  familiar  with  the  channels  through  wiiich  he  him- 


IN7  'R  OD  UCTION.  2 1 

self  may  become  infected,  or  the  means  by  which  he  may 
serve  as  a  carrier  of  infection  and  the  proper  precautions  for 
preventing  such  accidents.  As  an  educated  physician  he 
should  know,  and  as  a  conscientious  physician  he  should 
practise  these  precepts  for  the  good,  not  only  of  his  own 
patients,  but  of  the  community  of  which  he  forms  a  part.  The 
medicine  of  the  period  tends  more  and  more  in  the  direction 
of  prevention,  and  if  the  physician  proposes  to  keep  himself 
abreast  of  the  times  it  is  imperative  that  he  be  in  touch  with 
the  advances  along  these  lines.  While  ignoring  the  subject  a 
new  medicine  grows  up  about  him,  and  he  is  suddenly  aware 
of  his  presence  in  an  atmosphere  unfamiliar  and  wholly 
uncongenial — an  atmosphere  that  he  does  not  appreciate,  and 
with  which  he  experiences  no  intelligent  sympathy. 

From  time  to  time  the  teachings  of  hygiene  are  assailed  by 
hostile  attacks,  and  proof  is  demanded  that  the  practice  of 
sanitary  precepts  has  resulted  in  the  betterment  of  the  condi- 
tions under  which  mankind  lives,  in  the  prevention  of  disease, 
or  in  the  saving  of  life.  While  it  cannot  truthfully  be  said 
that  every  so-called  sanitary  precaution  is  beneficial  or  neces- 
sary, or  that  every  article  in  the  sanitary  code  is  based  on 
that  which  is  proved  to  be  sound,  we  can  nevertheless  combat 
adverse  criticism  with  an  array  of  evidence  that  should  con- 
vince the  most  sceptical  as  to  the  importance,  yea,  the  pro- 
found necessity,  of  an  intelligent  sanitary  control  of  the  con- 
ditions under  which  we  live.  For  instance,  to  cite  a  few  of 
the  triumphs  of  hygiene  :  Until  the  beginning  of  the  present 
century  the  average  mortality  from  small-pox  in  Prussia  was 
3  per  looo  of  population.  In  times  of  epidemics  this  ratio 
was  commonly  very  much  increased.  Since  the  introduction 
of  compulsory  vaccination  the  mortality  from  this  disease  has 
fallen  to  its  present  figure  of  0.03  per  1000  of  population, 
and,  as  Fliigge  states,  cases  of  small-pox  are  now  looked 
upon  in  many  provinces  of  Prussia  as  medical  curiosities. 

During  the  seventeenth  and  eighteenth  centuries  the 
annual  death-rate  from  this  disease  in  London  ranged  from  2 
to  4  per  1000  of  population  ;  with  the  introduction  of  general 
vaccination  it  had  fallen  for  the  interval  between  1883  and 


22  HYGIENE    OE   TRANSMISSIBLE   DISEASES. 

1892  to  0.073  per  1000.  Schulz  states  that  by  the  calcula- 
tions of  the  Imperial  Health  Bureau  at  Berlin,  based  upon 
the  statistics  of  mortality  for  small-pox  for  the  periods 
between  1845  ^'''d  1869,  and  1875  and  1885,  at  least  74,000 
lives  have  been  saved  through  vaccination  in  Prussia  alone. 

Reductions  in  the  mortality  from  this  disease  analogous  to 
those  just  cited  have  occurred  in  all  countries  where  vaccina- 
tion has  become  general. 

During  the  seventeenth  and  eighteenth  centuries  a  very 
large  proportion  of  sickness  and  death  in  the  navies  and  in 
the  merchant  service  was  due  to  scurvy,  and  no  inconsider- 
able number  in  public  institutions,  hospitals,  jails,  reform- 
atories, workhouses,  etc.,  were  from  the  same  cause.  By 
virtue  of  proper  attention  to  diet,  cleanliness,  and  habitation, 
scur\y  has  practically  disappeared  from  among  civilized 
peoples. 

Typhus  fever,  also  so  frequent  in  former  times  among  the 
inmates  of  overcrowded  hospitals  and  other  public  institutions, 
has,  under  modern  sanitary  conditions,  become  a  rarity. 

By  attention  to  the  drainage  of  soils  and  the  introduction 
of  pure  water  for  domestic  purposes,  it  has  been  demon- 
strated that  cholera  and  typhoid  fever  can  be  almost  elimi- 
nated. No  more  striking  instance  of  this  can  be  cited  than 
the  remarkable  reduction  in  the  typhoid  death-rate  in  the  city 
of  Munich.  In  1856  the  mortality  from  typhoid  in  Munich 
was  2.91  per  lOOO  of  population.  At  that  time  the  soil  of 
the  city  was  honeycombed  with  cesspools,  and  a  large  part 
of  the  water-supply  of  the  city  was  obtained  from  wells  and 
pumps  sunk  in  this  soil.  Between  1856  and  1887  the  condi- 
tion of  the  city  underwent,  at  several  conspicuous  periods,  a 
radical  .sanitary  reform.  The  cesspools  were  filled,  and  the 
introduction  of  new  ones  was  prohibited.  An  elaborate  system 
of  .sewers  was  introduced,  pumps  and  wells  were  abandoned, 
and  a  pure  water-supply  was  brought  from  a  source  beyond 
suspicion  of  pollution.  As  a  result  of  all  this,  the  mortality 
from  typhoid  fever  fell,  and  in  1887  it  had  reached  the  very 
low  ratio  of  o.i  per  lOOO  c>f  poj)ulation,  a  reduction  of  about 
96.6  per  cent,  in  the  deaths  from  this  di.sease  alone. 


INTRODUCTION.  23 

Within  less  than  one  year  after  the  adoption  of  approved 
methods  for  the  purification  of  the  water-supply  of  Lawrence, 
Mass.,  the  death-rate  from  typhoid  fever  was  reduced  nearly 
59  per  cent.,  and  in  Chicago  the  deaths  from  this  disease  were 
diminished  approximately  60  per  cent,  within  a  year  after  the 
domestic  water-supply  was  obtained  from  a  non-polluted 
source. 

As  a  result  of  the  proper  drainage  of  soils,  a  diminution  in 
the  frequency  of  pulmonary,  intestinal,  and  malarial  troubles 
has  everywhere  been  observed. 

These  few  illustrations,  not  to  mention  the  advantages  that 
have  accrued  from  increased  attention  to  personal  hygiene, 
to  diet  and  raiment,  to  the  laws  of  disinfection,  isolation,  and 
quarantine,  should  serve  as  convincing  proof  that  the  efforts 
of  the  hygienist  have  not  been  in  vain  ;  that  they  have  not 
only  been  of  enormous  benefit  to  mankind,  but  that  with  the 
increased  store  of  knowledge  that  is  constantly  accumulating, 
they  are  still  further  capable  of  such  benefits.  Already  count- 
less lives  have  been  saved ;  we  are  told  that  the  longevity  of 
the  human  race  has  been  increased,  and  in  eveiy  way  the  con- 
ditions under  which  man  lives  are  better  than  they  were  a  {ey^i 
years  back. 

In  citing,  as  illustrations,  the  advances  that  have  been  made 
along  the  Hnes  of  hygiene  and  the  good  that  has  been  de- 
rived from  them,  it  is  not  our  desire  to  leave  the  impression 
that  the  millennium  has  arrived  ;  that  our  stock  of  knowledge 
on  the  subject  is  complete  or  satisfactory  in  all  details  ;  or 
indeed  even  that  the  knowledge  we  possess  is  utilized  to  the 
extent  that  its  importance  demands.  When  we  realize  that 
the  majority  of  all  deaths  is  still  from  preventible  causes,  most 
of  which  are  already  quite  familiar  to  us,  it  is  manifest  that 
this  must  be  in  a  large  measure  due  to  an  indifference  on  our 
part  to  put  into  practice  even  that  knov/ledge  which  we 
already  possess  for  their  prevention.  The  great  majority  of 
deaths  result  from  infection,  from  insufficient  attention  to  diet, 
and  from  want  of  care  with  regard  to  the  temperature  of  the 
body — that  is  to  say,  they  are  the  direct  outcome  of  our  sur- 
rounding  circumstances.     We   consider  it  quite   within    the 


24  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

bounds  of  moderation  and  discretion  to  declare  that,  by  the 
indefatigable  practice  of  the  sanitary  precepts  now  known  to 
be  sound  with  regard  to  the  prophylaxis  and  management  of 
the  commoner  infectious  diseases,  to  the  hygiene  of  infancy, 
to  diet  and  clothing,  the  death-rate  from  preventible  causes 
could  be  conspicuously  reduced,  and  this,  too,  without  the 
addition  of  a  single  new  fact  to  the  knowledge  that  we  already 
possess. 


SECTION    I. 
THE  CAUSATION  OF  DISEASE. 


As  has  been  stated,  the  object  of  hygiene  is  to  prevent  dis- 
ease. It  is  therefore  necessary  to  an  understanding  of  the 
means  employed  in  securing  this  end  that  we  possess  a  clear 
comprehension  of  the  factors  concerned  in  the  causation  and 
dissemination  of  disease. 

The  causative  factors  in  disease  are  manifold  ;  they  differ  in 
nature  the  one  from  the  other,  and  are  of  varying  degrees  of 
importance  in  their  relation  to  morbid  conditions. 

In  considering  this  phase  of  our  studies  it  is  well  to  bear 
in  mind  from  the  beginning  that  beyond  traumatisms  and 
direct  poisons  there  is  probably  no  single,  absolute  cause  of 
disease,  but  that  the  abnormal  state  we  call  disease  represents 
the  termination  of  a  chain  of  circumstances  the  various  links 
of  which,  while  having  more  or  less  of  a  direct  bearing  upon 
the  others,  are  of  different  degrees  of  importance  to  the  proc- 
ess. Thus,  by  way  of  illustration,  we  say  that  tuberculosis  is 
caused  by  a  specific  micro-organism,  and  no  one  doubts  this  ; 
but  at  the  same  time  there  is  no  one  who  believes  for  an  in- 
stant that,  if  to  a  number  of  individuals  in  sound  health  this 
micro-organism  gains  access,  tuberculosis  will  with  certainty 
result  in  all  cases.  There  are  other  factors  that  come  into 
play  and  must  be  taken  into  consideration.  On  the  one  hand, 
there  are  circumstances  that  modify  the  disease-producing 
powers  of  the  micro-organism,  so  that  at  one  time  it  may  be 
comparatively  feeble  as  regards  this  property,  while  at  another 
it  is  infective  to  the  fullest  extent.  On  the  other  hand,  there 
are  modifying  influences  constantly  at  work  upon  the  indi- 
vidual, some  of  them  placing  him  in  a  condition  to  survive 
exposure  to  the  most  virulent  forms  of  infection,  while  others 

25 


26  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

SO  modify  the  normal  vital  resistance  with  which  nature  has 
provided  him  that  he  readily  falls  a  prey  to  what  would  other- 
wise be  a  comparatively  insignificant  foe.  In  other  words, 
certain  influences  to  which  man  is  exposed  during  the  course 
of  his  existence  predispose  him  to  disease  in  general,  while 
others  are  concerned  in  directly  exciting  certain  definite  groups 
of  symptoms  and  pathological  manifestations,  which  are  usu- 
ally classed  as  specific  diseases.  In  considering  the  causation 
of  definite  or  specific  diseases  it  is  impossible  to  ignore  those 
surrounding  conditions  that  predispose  to  them.  Reverting 
to  our  illustration,  the  exciting  or  direct  cause  of  tuberculosis, 
with  all  its  varied  expressions,  is  Bacillus  tJiberciilosis,  while 
the  predisposing  or  indirect  causes  may  be  numerous — as 
age,  race,  occupation,  unsanitary  surroundings,  and  heredity. 

In  their  relation  to  specific  disease-processes  in  general,  the 
causative  factors  are  therefore  usually  classed  as  Exciting  or 
Direct  and  Predisposing  or  Indirect. 

Predisposing  Causes  of  Disease. — By  this  term  is 
meant  those  conditions  with  which  man  is  surrounded  that 
have  a  tendency  to  so  reduce  his  normal  vital  powers  that  he 
is  no  longer  capable  of  resisting  the  inroads  of  the  direct, 
exciting  cau.ses  of  disease.  The  term  "  vital  "  or  "  animal 
resistance  "  was  at  one  time  vaguely  employed  in  explanation 
of  the  efforts  of  the  tissues  to  evade  infection.  In  the  light 
shed  by  modern  investigation  upon  the  means  of  defence 
possessed  by  the  animal  organism  for  the  resistance  of  dis- 
ea.se,  vital  resistance  signifies  a  group  of  animal  functions, 
some  of  which  are  capable  of  ready  demonstration,  that  is 
pos.sessed  by  every  living  being  in  health,  and  through  the 
exercise  of  which  the  body  is  enabled  to  withstand,  within 
limits,  the  influence  of  detrimental  agencies. 

We  now  know  that  the  circulating  fluids,  certain  wandering 
cells,  and  certain  fixed  cells  of  the  animal  economy  are 
directly  antagonistic  to  many  of  those  particulate  causes  of 
disea.se  known  as  micro-organisms  ;  that  through  the  exercise 
of  these  vital  functions  invading  bacteria  arc  often  destroyed 
before  sufficient  time  has  elapsed  for  them  to  multiply  and 
evolve  their  products  which  are  instrumental  in  disturbance 


THE    CAUSATION  OF  DISEASE.  27 

of  function  and  destruction  of  tissues.  We  have  reason  for 
believing,  moreover,  that  within  these  same  fluids  and  cells 
lies  also  the  power  of  neutralizing  to  a  certain  extent  the 
poisonous  products  of  bacteria  which  themselves  may  not  be 
destroyed  by  the  body. 

The  highest  expression  of  this  vital  phenomenon  is  natu- 
rally found  in  the  healthy  being.  Agencies  that  tend  to  re- 
duce the  general  health,  such  as  exposure,  fatigue,  malnu- 
trition, debauch,  etc.,  tend  likewise  to  diminish  the  vital 
resistance,  and  in  this  manner  render  the  individual  more 
susceptible  to  disease. 

Age. — As  a  factor  in  predisposing  to  disease,  the  influence 
of  age  cannot  be  ignored.  To  certain  maladies  the  young 
are  more  prone  than  the  old,  while  to  others  the  reverse  is 
the  case.  The  greatest  number  of  deaths,  and  hence  the 
greatest  amount  of  sickness,  occurs  among  the  very  young 
and  the  very  old — /.  e.,  before  the  age  of  five  and  after  the 
age  of  sixty-five  to  seventy  years,  indicating  that  at  these 
periods  the  vital  processes  are  at  the  one  time  but  imperfectly 
developed,  while  at  the  other  they  are  declining  in  efficiency. 
There  are  certain  diseases  common  to  all  ages,  though  their 
pathological  manifestations  may  vary  according  to  the  age  of 
the  subject  affected.  For  example,  tuberculosis  is  seen  in  the 
infant,  the  adult,  and  the  aged  ;  but  in  childhood  its  expres- 
sions are  most  frequent  in  the  lymphatic,  the  osseous,  and  the 
serous  tissues,  while  in  maturity  and  old  age  the  lungs  are 
usually  involved  when  tuberculosis  is  anywhere  present  in  the 
body  (Louis's  law). 

In  general,  it  may  be  said  that  during  infancy  and  child- 
hood the  diseases  most  frequently  encountered  are  those  con- 
nected with  the  development  of  anatomical  structures  and  the 
establishment  of  physiological  functions.  To  this  may  be 
added  those  dependent  upon  congenital  defects  and  upon 
special  hereditary  tendencies,  those  consequent  upon  the 
neglect  of  careless  and  inexperienced  mothers,  those  result- 
ing from  undue  exertion,  as  of  occupation,  during  and  after 
pregnancy,  those  that  occur  in  consequence  of  improper  food 
and  clothing,  and  lack  of  cleanliness  and  pure  air.     Certain 


28  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

of  the  acute  exanthemata,  as  measles,  scarlatina,  rotheln, 
varicella,  etc.,  are  much  more  frequent  in  childhood  and 
early  youth  than  later  ;  while  others,  as  erysipelas,  variola, 
and  typhus  fever,  may  appear  at  any  period  of  life.  Typhoid 
fever  is  most  frequent  in  youth  and  early  adult  life.  Its 
greatest  frequency  is  seen  between  the  ages  of  fifteen  and 
twenty-five  years.  After  forty-five  years  it  is  comparatively 
rare. 

The  frequency  of  the  acute  exanthemata  in  childhood  is 
probably  accountable  for  their  comparative  infrequency  in 
adult  life,  for  we  have  reason  to  believe  that  a  single  non- 
fatal attack  of  either  or  all  of  these  maladies  in  childhood 
affords  a  more  or  less  permanent  protection — immunity — to 
that  child  from  subsequent  attacks  of  the  same  disease  at  a 
later  period  of  its  life. 

Adult  life  is  not  conspicuously  more  prone  to  one  than  to 
another  group  of  diseases.  At  this  period  man's  physio- 
logical processes  are  developed  and  in  active  operation,  and 
his  freedom  from  or  affliction  with  disease  will  depend  very 
largely  upon  the  conditions  under  which  he  lives.  If  circum- 
-Stances  permit  him  to  lead  a  rational  life,  giving  due  attention 
to  exercise,  diet,  clothing,  cleanliness,  and  hygienic  surround- 
ings, there  is  no  reason  why  he  should  not  be  comparatively 
safe  from  disease.  If,  on  the  other  hand,  his  life  is  passed 
under  conditions  of  extreme  poverty,  overcrowding,  intem- 
perance, exposure  to  excesses  of  heat,  cold,  or  moisture,  foul 
air,  bad  food,  impure  water,  uncleanliness,  and  exposure  to 
contagion,  there  are  equally  good  reasons  for  expecting  him 
to  fall  a  ready  prey  to  disease,  for  these  are  the  underlying- 
causes  of  the  vast  majorit)'  of  sickness  and  death  among  all 
ages  in  great  cities. 

The  diseases  incidental  to  old  age,  a  period  difficult  to 
define  accurately  because  of  the  variation  in  the  time  of  its 
onset  in  different  individuals,  are  those  that  depend  upon  the 
gradual  loss  of  power  on  the  part  of  the  organs  to  perform 
their  normal  physiological  functions,  with  the  consequent  dis- 
turbance of  nutrition  and  the  multiform  abnormal  manifesta- 
tions that  this  defect  entails.      In  short,  the  diseases  of  age 


THE    CAUSATION   OF  DISEASE.  29 

are  mainly  degenerative  in  their  nature,  and  simply  indicate 
irregularities  that  are  incidental  to  the  progressive  wearing 
out  of  the  machineiy  of  life.  Among  the  commoner  may  be 
mentioned  those  affecting  the  heart  and  arteries,  those  of  the 
renal  and  hepatic  systems,  catarrhal  conditions  of  the  mucous 
membranes,  diseases  consequent  upon  intemperance,  rheu- 
matic and  gouty  affections,  cancers,  and  tumors. 

Sex. — With  regard  to  certain  diseases  that  depend  upon 
the  existence  of  particular  anatomical  structures,  it  is  obvious 
that  sex  is  an  important  predisposing  factor,  particularly  in 
connection  with  those  maladies  that  affect  the  organs  by 
which  the  sexes  are  differentiated. 

The  influence  of  sex  does  not,  however,  cease  here.  With 
regard  to  other  diseases,  and  indeed  to  disease  in  general,  it 
has  a  manifestly  important  bearing.  For  some  reason  or 
reasons,  for  there  are  probably  many  to  explain  it,  the  gen- 
eral death-rate  among  females  is  uniformly  lower  than  that 
among  males,  and  statisticians,  as  a  rule,  assign  to  women  a 
greater  expectation  of  life  than  to  men.  On  reflection  we 
might  be  prepared  for  this,  for  by  the  nature  of  things  males 
are  brought,  during  the  course  of  their  daily  life,  into  closer 
contact  with  a  greater  variety  of  surrounding  conditions  that 
may  influence  their  health  than  are  women.  Man's  exposure 
to  accident  is  also  much  greater. 

With  regard  to  certain  diseases,  the  influence  of  sex  is  very 
apparent,  and  in  some  cases  this  influence  varies  conspicu- 
ously according  to  age.  In  some  instances  the  influence  of 
sex  does  not  appear  until  the  advent  or  after  the  age  of 
puberty.  Before  this  period  the  sexes  are  less  markedly 
differentiated  in  their  relation  to  disease.  By  way  of  illustra- 
tion : — This  influence  of  age  and  sex  upon  mortality  is  very 
strikingly  brought  out  in  connection  with  cancer,  anemia,  and 
typhoid  fever.  For  the  six  years  ending  with  May  31,1 890, 
according  to  the  last  (eleventh)  United  States  Census,  there 
occurred  in  New  York  City  among  the  white  population  48 
deaths  from  cancer  in  individuals  under  fifteen  years  of  age ; 
of  these  24  were  in  males  and  24  in  females  ;  for  the  ages 
between  fifteen  and  forty  years  there  were  782   deaths  from 


30 


JIYGIENE    OF   TRANSMISSIBLE   DISEASES. 


the  same  cause ;  of  these  222  were  in  males  and  560  in 
females  ;  while  for  all  over  forty  years  of  age  the  number  of 
deaths  from  cancer  was  3952,  of  which  1299  occurred  in 
males  and  2653  in  females. 

Anemia  resulted  fatally  in  49  individuals  under  fifteen 
years  of  age ;  of  these  22  were  males  and  27  females  ;  it 
caused  the  death  of  64  persons  between  the  ages  of  fifteen 
and  forty  years ;  of  these  1 8  were  males  and  46  females ; 
while  for  the  ages  over  forty  years  there  were  56  deaths,  of 
which   19  were  males  and  37  females. 

The  deaths  from  typhoid  fever  among  those  under  fifteen 
years  of  age  were  290,  of  which  152  were  males  and  138 
were  females  ;  among  the  deaths  of  those  between  fifteen  and 
forty  years  of  age  from  the  same  cause,  there  were  828  males 
and  526  females,  while  the  deaths  of  those  over  forty  years 
were  found  to  be  213  males  and  148  females.  In  the  case  of 
cancer  it  is  clear  that  advancing  years  and  female  sex  offer 
conditions  favorable  to  its  development.  In  the  case  of 
anemia  there  seems  to  be  no  preference  for  the  sexes  before 
puberty.  After  that  time  until  the  period  of  old  age  females 
are  much  more  liable  than  males.  With  typhoid  fever  we 
find  the  greatest  number  of  deaths  during  the  period  of 
youth  and  early  adult  life,  but  the  greater  number  of  deaths 
is  among  males '  (see  Table  I.). 


Taulk  I. — Deaths  among  the  ivhite population  of  New  YorJz  City 
from  Anemia,  Typhoid  Fever,  and  Cancer  dui'ing  the  six 
years  ending  May  ji,  i8go,  with  distinction  of  age  and  sex. 


Anemia. 

Typhoi 

d  Fever. 

Cancer. 

Males. 

Females. 

Males. 

152 
828 
213 

1193 

Females. 

Males. 

Females. 

Under  15  yeans      .    . 

From  15  to  40  years  . 

Over  40  years     .    .    . 

Totals  .... 

22 
18 

59 

27 
46 

37 
no 

138 
526 
148 

24 

222 

1299 

24 

560 

2653 

3237 

812 

1545 

'  The  numerical  method  here  employed  may  not  be  acceptable  in  the 
light  of  accurate  statistical  methods.  The  figures  represent  only  the  absolute 
numbers  and  not  the  relation  of  such  numbers  to  a  fixed  standard  of  compar- 
ison. They  are,  however,  quite  ne;ir  enough  to  accuracy  to  serve  as  a  fair 
illustration. 


THE    CAUSATION  OF  DISEASE.  3 1 

According  to  the  same  document,  males  afford  a  greater 
number  of  deaths  than  females  from  typhoid  fever,  venereal 
diseases,  alcoholism,  lead-  and  other  forms  of  poisoning, 
hydrocephalus,  tetanus,  and  trismus  nascentium,  convulsions, 
diseases  of  the  brain  and  cord,  angina  pectoris,  aneurysm, 
laiyngitis,  diseases  of  the  liver,  urinary  calculus  and  renal  dis- 
eases, diseases  of  the  bladder  and  genito-urinary  tract,  dis- 
eases of  the  bones,  of  the  spleen,  and  accidents.  Females 
succumb  more  frequently  than  males  to  malaria,  cancer, 
anemia,  dropsy,  ascites,  diseases  of  the  stomach,  peritonitis, 
and,  of  course,  to  diseases  of  the  female  reproductive  organs, 
and  to  those  incidental  to  pregnancy  and  childbirth.  In 
some  instances  the  reason  for  these  differences  is  manifest ;  in 
others  it  is  in  obscurity. 

Race. — It  is  a  well-known  fact  that  the  predispositions  of 
the  different  races  of  mankind  to  particular  forms  of  disease 
are  not  uniform.  Some  exhibit  a  pecuHar  susceptibility  to 
certain  maladies,  while  others  possess  a  comparative  degree 
of  immunity  from  them. 

In  some  instances  this  is  explainable  through  the  pro- 
longed exposure  of  races  to  particular  diseases,  resulting  in 
their  acquisition  of  a  greater  degree  of  tolerance  to  them 
than  is  seen  to  be  possessed  by  other  races,  or  other  portions 
of  the  same  race,  that  have  not  been  similarly  exposed. 

It  is  difficult  to  obtain  trustworthy  data  that  are  of  general 
application  in  deciding  the  influence  of  race  upon  disease, 
because  of  the  many  determining  factors  that  come  into  play. 
Nevertheless,  through  vital  statistical  studies  of  groups  of 
people  of  different  races  living  under  various  conditions,  we 
have  obtained  data  of  more  or  less  importance  that  are  indic- 
ative of  the  relative  frequency  of  different  diseases  among 
them.  Whether  the  results  obtained  by  this  method  are 
entirely  trustworthy  or  not  it  is  difficult  as  yet  to  decide  ;  the 
differences,  as  said,  may  depend  upon  so  many  surrounding 
circumstances — the  social  conditions,  with  all  that  these  entail, 
under  which  the  different  peoples  were  living  at  the  time  of 
the  observation  being  perhaps  the  most  important. 

With  regard  to  the  influence  of  race  on  disease  in  general, 


32  HYGIENE    OE   TKAXSMISSIBLE   DISEASES. 

there  is  more  or  less  disagreement  of  opinion,  thoui^ii  in 
several  special  instances  there  is  striking  evidence  in  favor  of 
such  a  relation.  There  is  a  general  consensus  of  opinion 
that  the  negro  is  less  susceptible  to  yellow  fever  and  malaria 
than  the  white  man,  and  the  white  man  less  susceptible  to 
pulmonary  troubles  and  cholera  than  the  black  man  ;  that 
the  German  oftener  falls  a  prey  to  cancer  than  his  Celtic 
cousin  ;  and  that  the  Jew  escapes  more  frequently  from  dis- 
eases of  a  tuberculous  nature  and  from  epidemic  diseases 
than  does  any  other  race  of  mankind.  But  when  we  attempt 
to  carry  the  investigation  further  confusing  factors,  varying  in 
the  degree  of  their  importance,  are  encountered,  and  the 
results  obtained  cannot  be  considered  as  entirely  reliable  for 
purposes  of  generalization.  It  is  probable  that  there  is  no 
disease  to  which  mankind  is  liable  from  which  any  race  of 
man  possesses  absolute  natural  (/.  c,  congenital)  immunity. 

For  the  study  of  race-influence  upon  the  frequency  of  and 
mortality  from  special  diseases  among  different  peoples,  living 
under  approximately  similar  conditions  and  equal  degrees  of 
exposure  to  disease,  the  United  States  with  their  large  popu- 
lation, con.sisting  of  representatives  of  almost  every  nation, 
the  diversity  of  their  geological  and  climatic  conditions,  and 
especially,  as  in  the  great  cities,  the  more  or  less  intimate  ad- 
mixture of  the  different  races,  offer  an  unusual  opportunity. 

Important  light  is  shed  upon  this  matter  through  the  Cen- 
sus and  Vital  Statistics  of  our  people,  taken  ever>'  ten  years. 
In  the  compilation  of  these  reports  it  is  cu.stomary  to  compare 
the  death-rates,  or  actual  deaths  (fair  indices  of  .sickness)  from 
different  causes  among  the  foreign  population,  with  the  deaths 
among  the  native  white  and  colored  population,  and  while 
the  deductions  drawn  from  this  method  are  of  undoubted 
value  in  illu.strating  the  relative  susceptibilities  of  these  vari- 
ous peoples  to  different  di.seases,  it  mu.st  be  remembered  that 
the  comparisons  are  made  between  peoples  of  very  different 
social  conditions,  and  that  they  are  not  therefore  as  trust- 
worthy as  they  would  be  were  the  inequality  in  this  respect 
less  ;  though  they  undoubtedly  indicate  the  frequency  of  dis- 
ea.se  under  the  existing  circumstances. 


THE   CAUSATION  OF  DISEASE. 


33 


The  census  of  1 890  for  the  city  of  New  York  shows  the 
lowest  death-rate  from  all  causes  to  have  been  among  the 
Russians  and  Poles,  the  majority  of  whom  in  this  countiy  are 
of  the  Semitic  race,  while  the  highest  general  death-rate  was 
among  the  Italians.  The  fallacy  and  inconstancy  of  the  re- 
sults obtained  by  this  method  are  best  illustrated  by  the 
results  of  statistics  compiled  along  the  same  lines  and  at  the 
same  time  in  Boston  and  Philadelphia.  In  Boston  the  high- 
est death-rate  from  all  causes  and  at  all  ages  was  among  the 
Irish,  and  the  lowest  among  the  French  ;  while  in  Philadel- 
phia the  native  whites  experienced  the  greatest  loss  from 
death  and  the  Bohemians  the  least.  The  high  (relatively 
speaking)  death-rate  among  the  native  white  population  of 
Philadelphia  is  probably  due  to  the  relatively  larger  number 
of  married  and  marriageable  native  Americans  in  that  city, 
and  consequently  a  larger  number  of  young  children  than  are 
found  in  any  of  the  other  groups  (Billings). 


Table  II.  —  Comparing  the  death-i'ates  per  1000  of  white  and 
negro  populations  for  the  six  years  eliding  with  May  ji,  i8go 
{Eleventh  United  States  Census)  : 

White.  Colored. 


Boston      

-    •    •  23.71 

31.92 

New  York 

.    .    .  29.86 

,     33-27 

Brooklyn . 

.    .  25.90 

30.54 

Philadelphia 

.    .    .  22.69 

31-25 

Baltimore 

.    .    .  21.98 

35-99 

District  of  Columbia  .    .    . 

•    •    •  1975 

37.00 

A  conspicuously  constant  racial  influence  upon  suscepti- 
bility to  disease  is  observed  in  comparisons  between  the  death- 
rates  among  the  white  and  negro  populations.  In  eighteen 
southern  and  four  northern  cities  the  eleventh  census  shows 
that  the  general  death-rate  for  all  ages  was  in  each  case 
greater  among  the  colored  than  among  the  white  natives 
(see  Table  II.).  It  is  not  unlikely,  however,  that  this  is 
due  to  social  condition  as  much  as,  if  not  more  than,  to 
racial  peculiarity. 

As  has  been  stated,  the  negro  is  less  susceptible  to  yellow 
fever  than  the  white  man,  though  this  not  always  the  case. 
3 


34  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

Instances  are  recorded  in  which  the  mortality  of  negroes  from 
this  disease,  during  times  of  epidemics,  was  as  great  as  among 
the  white.  The  comparative  immunity  of  the  negro  is  prob- 
ably accjuired,  as  it  has  been  observed  that  negroes  who  are 
born  and  raised  in  countries  and  localities  where  the  disease 
is  unknown  are  practically  as  susceptible  as  whites  when  ex- 
posed to  the  infection.  It  may  or  may  not  be  due  to  acquired 
tolerance,  or  "  acclimatization,"  as  it  is  sometimes  called,  that 
a  similarly  relatively  low  degree  of  susceptibility  of  the  negro 
to  malaria  is  observed;  of  614  cases  of  malaria,  seen  in  Bal- 
timore, and  described  and  analyzed  by  Thayer  and  Hewetson, 
585  occurred  in  whites,  while  only  29  were  in  colored  per- 
sons. On  the  other  hand,  "  there  is  a  general  consensus  of 
opinion  that  the  negro  is  especially  liable  to  Asiatic  cholera  " 
(Hirsch).  According  to  Walther  (quoted  from  Hirsch),  the 
mortality  from  cholera  in  Guadeloupe  during  the  epidemic  of 
1865  was  divided  among  the  following  peoples  in  the  follow- 
ing percentages  :  Chinese,  2.7  per  cent. ;  Hindoos,  3.26  per 
cent.;  whites,  4.31  per  cent.;  mulattos,  6.32  per  cent.,  and 
negroes,  9.44  per  cent.  During  the  epidemic  of  1866  in  this 
countiy  the  mortality  from  cholera  among  the  white  troops 
(U.  S.  army)  was  ']'] ,  and  that  among  the  colored  1 35  per  lOOO 
(Hirsch).  By  the  vital  statistics  of  New  York  city,  census 
of  1890,  consumption,  pneumonia,  heart  disease,  puerperal 
diseases,  and  diseases  of  the  urinaiy  apparatus  were  found  to 
be  more  fatal  among  the  negro  than  the  native  white  popula- 
tion ;  while  scarlet  fever,  diphtheria,  croup,  diarrheal  diseases, 
measles,  whooping  cough,  diseases  of  the  liver,  and  diseases 
of  the  nervous  system  were  more  fatal  to  the  native  white 
than  the  colored  race. 

The  table  given  on  page  35  (Table  III.)  presents  these 
relations  numerically. 

In  numerous  instances  the  Chinese  have  shown  a  con.spicu- 
ous  immunity  from  cholera. 

One  of  the  most  striking  examples  of  specific  racial  im- 
munity from  disease  is,  as  stated,  that  observed  among  the 
Jews.  While  they  are  attacked  by  the  general  run  of  dis- 
eases as  often  as,  and  sometimes  more  often  than,  Christians, 


THE    CAUSATION  OF  DISEASE. 


35 


yet  they  are  very  much  less  frequently  the  subjects  of  tuber- 
cular and  acute  epidemic  diseases  than  any  other  race  of 
mankind. 


Table  III. — Proportion  of  deaths  from  different  diseases  per 
100,000  of  mean  popiclation  in  the  city  of  New  York  for  the 
six  years  ending  May  ji,  i8go,  with  distinction  of  color  and 
nativity  : 


Scarlet  fever 

Diphtheria 

Croup      

Diarrheal  diseases 

Consumption 

Pneumonia 

Measles 

Whooping-cough 

Cancer  and  tumor 

Heart  disease  and  dropsy     .    . 
Childbirth  and  puerperal  diseases 

Diseases  of  the  liver 

Diseases  of  the  nervous  system  . 
Diseases  of  the  urinary  organs    . 


White 
(native). 


79-58 

179.46 

78.76 

383-24 

238.48 

280.15 

58.34 

54-24 

54.92 

130.00 

16.87 

24.05 

308. 64 

147.76 


White 
(foreign). 


9.89 
17-58 

8.59 
90.25 

483-83 

265.27 

6.56 

1.69 

102.61 

194-95 
38.01 

53-79 
197.06 
253-86 


Colored. 


II. II 

31-94 
13-19 

243.72 

774.21 

324-27 

15.28 

39-58 

45-13 

188.17 

23.61 

12.50 

240.25 

242.33 


Richardson  states  that  "  the  mortality  from  cholera  among 
them  is  so  small  that  the  very  fact  of  its  occurrence  has  been 
disputed From  epidemics  the  Jews  have  often  es- 
caped, as  if  they  possessed  a  charmed  life,"  In  "  The  Vital 
Statistics  of  the  Jews  of  the  United  States,"  compiled  by  Dr. 
Bilhngs  in  1890,  it  is  seen  that,  as  compared  with  the  popula- 
tion of  the  entire  United  States,  and  with  that  of  the  State  of 
Massachusetts,  the  Jews  "  suffered  a  relatively  greater  loss 
than  their  neighbors  by  deaths  from  diphtheria,  diarrheal  dis- 
eases, diseases  of  the  nervous  system  (and  especially  from 
diseases  of  the  spinal  cord),  from  diseases  of  the  circulator}^ 
system,  urinary  system,  bones  and  joints,  and  of  the  skin  ; 
while  their  mortality  has  been  relatively  less  from  tubercu- 
lar diseases,  including  scrofula,  tabes,  and  hydrocephalus,  than 
the  other  people  with  whom  they  are  compared." 

The  following  table  (Table  IV.),  abridged  from  this  report, 
shows  the  relative  difference,  as  regards  consumption,  scrof- 
ula, and  hydrocephalus,  numerically  : 


36  JIYGIEXE    OF   TRANSMISSIBLE   DISEASES. 

Taule  1\'. — Giving  the  male  Jew  is  Ji  deatJi-rate  from  Consump- 
tion, Serofula,  and  Hydrocephalus  per  1000  total  deaths  from 
known  causes,  as  compared  with  the  rates  similarly  calculated 
for  the  entire  population  of  the  United  States  in  1880  and  for 
that  of  Massachusetts  in  1888  : 


Diseases. 

Jews. 

All  United  States, 
1880. 

All  Massachusetts, 
1888. 

Consumption    .    .    . 

•  36-57 

108.79 

129.22 

Scrofula  and  tabes  . 

.     1.04 

6.74 

30.60 

Hytlrocephalus    .    . 

•     i-^l 

6-43 

11.74 

This  conspicuous  immunity  of  the  Jewish  race  from  disease 
has  attracted  the  attention  of  statisticians  in  several  countries 
of  the  world,  with  the  result  of  demonstrating  this  peculiarity 
to  be  pretty  uniform.  Quoting  from  the  researches  of  de  Neuf- 
ville,  at  Frankfort :  "  The  average  duration  of  the  life  of  the 
Jew  is  forty-eight  years  and  nine  months,  and  of  the  Christian 
thirty-six  years  and  eleven  months  ;  .  .  .  half  the  Jews  born 
reach  the  age  of  fifty-three  years  and  one  month,  whilst  half 
the  Christians  born  attain  the  age  of  thirty-six  years  only. 
A  quarter  of  the  Jewish  population  is  found  living  beyond 
seventy-one  years,  but  a  quarter  of  the  Christian  population 
is  found  living  beyond  fifty-nine  years  and  ten  months  only."  ^ 
As  an  explanation  of  this  vital  advantage  on  the  side  of  the 
Jews,  Richardson  .states  "  the  causes  are  simply  summed  up 
in  the  term  '  soberness  of  life.'  The  Jew  drinks  less  than  his 
'  even  Christian  ' ;  he  takes,  as  a  rule,  better  food  ;  he  marries 
earlier ;  he  rears  the  children  he  has  brought  into  the  world 
with  greater  personal  care  ;  he  tends  the  aged  more  thought- 
fully ;  he  takes  better  care  of  his  poor,  and  he  takes  better 
care  of  himself"  To  this  might  perhaps  be  added,  he  has 
inherited  traces  of  tlie  respect  shown  by  his  ancestors  for  the 
laws  of  Moses  for  the  hygienic  guidance  of  the  children  of 
Israel. 

It  woukl  be  vain  to  contend  tliat  the  observations  made 
under  this  lieading  and  the  statistics  presented  justify  dog- 

'  fie  Xeufville  :  Lebensdauer  und  Todesursachen  zwci  und  y.vvanzig  ver- 
schiedener  Stande  und  (Jewerbe,  nebst  vergleichender  Statistik  der  christlichen 
und  israelitisclien  Hevolkerung  Frankforts,  1855.  Lauerlander's  Verlag,  I'raii/;- 
forl,  a.  m.  (Tables  XIX.,  XX.,  XXI.,  pp.  115-116). 


THE    CAUSATION   OF  DISEASE.  37 

matic  generalizations.  They  are  simply  important  indica- 
tions that  are  liable  to  modifications  according  to  surrounding 
circumstances. 

Occupation. — It  is  generally  recognized  that  certain  kinds 
of  occupation  predispose  to  disease,  and  that  there  is  a  par- 
ticular tendency  on  the  part  of  those  that  follow  them  to 
special  groups  of  maladies.  In  fact,  it  may  be  said  that  there 
exists  more  or  less  of  a  parallelism  between  the  increase  in 
industries  and  the  increase  of  disease  and  death.  With 
regard  to  the  majority  of  occupations,  disease  is  due  less  to 
the  character  of  the  work  done  than  to  the  conditions  under 
which  it  is  performed,  for  moderate  work  of  almost  any  kind, 
when  done  under  favorable  conditions,  must  be  considered  as 
in  every  way  advantageous  to  the  physical,  moral,  and  mental 
well-being  of  the  worker. 

The  conditions  of  occupation  that  most  frequently  predis- 
pose to  ill-health  are  the  generally  poor  hygienic  surround- 
ings, such  as  overcrowding  in  poorly  ventilated,  improperly 
heated,  damp,  and  uncleanly  offices  and  workshops ;  the 
inhalation  of  dust-laden  atmosphere  ;  exposure  to  extremes 
of  weather,  as  heat,  cold,  and  excessive  moisture  ;  and  the 
consumption  of  food  that  is  neither  in  quality,  quantity,  nor 
mode  of  preparation  adequate  to  repair  the  tissue-loss  conse- 
quent upon  muscular  and  mental  exertion.  To  this  may 
be  added  the  evil  effects  of  working  in  cramped  or  con- 
strained attitudes,  particularly  such  as  interfere  with  the 
normal  action  of  the  heart  and  lungs ;  of  unusually  pro- 
longed mental  exertion  ;  and  of  those  occupations  affording 
constant  temptation  to  the  too  frequent  use  of  alcoholic 
stimulants  (see  Table  V.,  page  38). 

The  result  of  these  influences  manifests  itself  in  the  form 
of  either  local  or  general  reduction  of  vitality.  In  some  cases 
there  occurs  a  general  undermining  of  the  health  of  the  indi- 
vidual ;  in  others  the  effect  is  more  or  less  local,  and  is  con- 
fined to  those  tissues  directly  under  the  influence  of  the  hurt- 
ful conditions,  converting  them  into  points  of  least  resistance 
that  serve  as  portals  of  infection. 

A  large  proportion  of  industrial  occupations  predispose  to 


38  HYCIEXE    OF   TRAXSMISSIBLE  DISEASES. 

diseases  of  the  lungs,  through  the  inhalation  of  finely  divided 
particles  of  matter  in  the  form  of  dust.  This  tends  in  general 
to  pulmonary  tuberculosis  and  to  other  pulmonary  troubles, 
principally  chronic  bronchitis,  emphysema,  bronchiectasis,  and 
interstitial  pneumonia. 

Table  V. — Co)iiparativc  mortality  of  liquoi'  dealers  with  that  of 
men  generally  (  Ogle)  : 

Men  25  to  65  Years  of  Age. 

Diseases.  , ' ■ 

Liquor  Trade.         AH  Males. 

Alcoholism 55  10 

Liver  diseases 240  39 

Gout 13  3 

Diseases  of  the  nervous  system      .    .    .  200  1 19 

Suicide 26  14 

Diseases  of  the  urinary  system  ....  83  41 

Diseases  of  the  circulatory  system     .    .  140  120 

Other  causes 764  654 

-  All  causes 1521  1000 

According  to  Ogle,^  the  effect  of  dust-inhalation  appears  to 
differ  with  the  physical  character  of  the  dust  inhaled.  That 
from  ordinary  soft  wood  (as  inhaled  by  carpenters)  seems  to 
be  relatively  harmless,  while  that  from  hard  woods  (as  inhaled 
by  cabinet-makers)  is  much  more  irritating.  The  dusts  that 
seem  to  be  the  most  dangerous  to  the  tissues  of  the  respira- 
tory apparatus  are  those  encountered  in  the  various  textile 
works,  mineral  du.sts,  and  the  dusts  of  metals.  Cutlers,  file- 
workers,  stone-cutters,  and  cotton-wool  workers  show  a 
marked  tendency  to  pulmonary  tuberculosis.  A  singular 
exception  is  seen  in  the  coal-miners  ;  while  constantly  inhaling 
a  dust-laden  atmosphere,  usually  to  such  a  degree  as  to  result 
in  the  production  of  a  distinct  pathological  condition  of  the 
lungs  (anthracosLs),  the  mortality  from  pulmonaiy  consump- 
tion among  miners  is,  according  to  Ogle,  comparatively  low. 

Aside  from  its  irritating  influence  dust  may  and  often  does 
serve  as  a  direct  carrier  of  infection.  This  is  conspicuously 
the  case  when  numbers  of  individuals  are  constantly  together 
in  unkept  rooms.  With  regard  to  tuberculosis,  the  inhalation 
of  dust  contaminated  with  the  dried  sputum  from  consump- 

'   Trans.  Seventh  Congress  of  1  Ivi^icnc  and  Dcniop-apliv,  London,  1891. 


THE    CAUSATION   OF  DISEASE.  39 

tives  is  probably  one  of  the  most  common  channels  for  the 
dissemination  of  the  disease  ;  the  greater  frequency  of  the 
pulmonary  manifestation  of  this  malady  may  be  cited  in  sup- 
port of  this  opinion.  Disease-producing  agents  other  than 
that  concerned  in  the  causation  of  tuberculosis,  notably  the 
pyogenic  bacteria,  have  been  found  in  the  dust  of  localities 
occupied  by  individuals  suffering  from  suppurative  troubles. 

In  the  paper  presented  by  Dr.  Ogle,  quoted  above,  attention 
was  called  to  the  fact  that  "  there  are  some  occupations  of  so 
deadly  a  character  that  life-insurance  companies  will  have 
nothing  to  say  to  them,  refusing  to  insure  the  life  of  a  man 
engaged  in  them  on  any  terms  whatsoever ;  while,  on  the 
other  hand,  there  are  professions,  or  at  any  rate  there  is  one 
profession,  in  which  the  chances  of  longevity  are  so  high  that 
an  insurance  company  which  is  lucky  enough  to  number  a 
considerable  proportion  of  those  engaged  among  its  clients, 
advertises  the  fact  to  show  the  general  public  upon  what  a 
safe  basis  its  business  is  founded."  Dr.  Ogle  presents,  in 
illustration  of  the  influence  of  employment  on  mortality,  the 
following  table  (see  Table  VI.),  compiled  from  a  very  large 
number  of  observations  made  upon  men  between  the  ages  of 
twenty-five  and  sixty-five  years.  It  must  be  said,  with  regard 
to  such  results,  that  they  cannot  be  accepted  as  universally 
correct  indications  of  the  influence  of  occupation  on  mortality 
and  disease,  for  many  individuals  in  all  callings  are  constitu- 
tionally tainted,  or  probably  predisposed  by  inheritance  to 
particular  diseases,  before  they  select  their  life  calling ;  and 
also  that  the  death  or  disease  among  individuals  following  a 
given  trade  at  the  time  of  the  census  may  be  in  no  way 
dependent  upon  the  influence  of  that  calling,  but  rather  upon 
some  one  followed  by  them  at  an  antecedent  period. 

Among  the  various  industrial  pursuits  there  are  some  that 
expose  the  workmen  to  influences,  in  addition  to  those  gen- 
erally predisposing,  that  are  directly  concerned  in  the  causa- 
tion of  disease-conditions.  Such  occupations  involve  the 
manipulation  of  various  chemical  poisons,  such  for  instance 
as  phosphorus  by  match-workers  ;  arsenic,  by  makers  of  cer- 
tain pigments ;    poisonous  anilins,  by  those  engaged  in  their 


40 


JIYGIENE    OF   TRAiXSMISSIBLE  DISEASES. 


Table  \"I.  —  Coinparaiivc  mortality  of  moi,  tivcuty-Jivc  to  sixty- 
fivc  xcars  of  age,  in  different  occupations,  1881  to  188 j  (  Ogie)  : 


Comparative 
mortulily. 


Occupation. 
Clergymen,  priests,  and  min- 
isters   100 

Lawyers 152 

Medical  men 202 

tiardeners 108 

Farmers II4 

Agricultural  laborers  .  .  .  126 
Fishermen 143 

Commercial  clerks  .  .  .  .179 
Commercial  travellers  .  .  .  171 
Innkeepers,  liquor  dealers     .  274 

Inn,  hotel  service 396 

Brewers 245 

Butchers 211 

Bakers 172 

Corn  millers 172 

Grocers 139 

Drapers 159 

Shopkeepers  generally  .    .    .  158 

Tailors 189 

.Shoemakers  166 

Hatters 192 

Printers 193 

I>()()kbinders 2IO 


Occupation.  \  ... 

■^  mortality. 

Builders,  masons,  bricklayers  174 
Carpenters,  joiners  ....  147 
Cabinet-makers,  upholsterers  173 
Plumbers,  painters,  glaziers     216 

Blacksmiths 175 

Engine,  machine,  and  boiler 

makers 155 

Silk  manufacture 152 

Wool,  worsted  manufacture  .  186 
Cotton  manufacture    .    .    .    .196 

Cutlers,  scissor  makers  .    .    .  229 

Gunsmiths 186 

File  makers 300 

Paper  makers 129 

Glass  workers 214 

Earthenware  makers  .    .    .    .314 

Coal  miners 160 

Cornish  miners 331 

Stone,  slate  quarries  ....  202 

Cab,  omnibus  service  .  .  .  267 
Railway,  road  laborers  .  .  .  185 
CosteiTnongers,  hawkers,  and 

street  sellers 338 


mantifacturc  ;  lead,  by  file-makers,  painters,  and  plumbers; 
mercury,  by  hatters-  and  gilders.  Brass-founders  and  those 
who  work  in  copper  and  zinc  are  subject  to  a  peculiar  form 
of  ague — "brass-founders'  ague."  The  continuous  inhalation 
of  irritating  and  irrespirable  gases  likewise  results  in  diseased 
conditions  of  the  air-passages — the  direct  results  of  such  con- 
ditions— and  likewise  in  constitutional  poisoning.  Among 
these  agents  may  be  mentioned  the  vapors  of  iodine  and 
bromine,  besides  chlorine,  ammonia,  arsenuretted  and  phos- 
phoretted  hydrogen,  nitrous  and  sulphurous  acids,  and  carbon 
monoxide  and  dioxide. 


THE    CAUSATION   OF  DISEASE. 


41 


Density  of  Population — Crowding. — ^It  is  a  matter  of 
common  observation  that  sickness  and  death  are  most  fre- 
quent in  those  communities  where  large  numbers  of  people 
are  crowded  together  in  comparatively  close  quarters  under 
the  conditions  of  poverty  that  such  an  existence  entails. 

The  accentuation  of  death-rate  resulting  from  the  condi- 
tions concomitant  with  excessive  density  of  population,  while 
manifest  for  all  ages,  is  conspicuously  evident  among  the 
very  young  of  such  a  community.  The  following  table  serves 
to  illustrate  this  strikingly  (Table  VII.). 

Table  VII. — Showiug  relation  between  death-rafe  per  1000  and 
density  of  population  in  seven  groups  of  districts  in  England 
and  Wales  {exclusive  of  London  ^)  .• 


Persons  to  i  sq.    1 
mile     .    ,    .    .    ) 

166 

186 

379 

1718 

4499 

12,357 

65,823 

Mean  death-rate  | 
at  all  ages  .    .    ) 

16.75 

19.16 

21.88 

24.90 

28.08 

32-49 

38.62 

Mean  death-rate    (^ 
under  5  years     / 

37.80 

47-53 

63.06 

82.10 

95-04 

III. 90 

139-52 

Mean  '  birth-rate    | 

per     1000    of     \ 

30.2 

32.2 

35-8 

38.7 

40.2 

37-3 

37-6 

living  .    .    .    .   j 

In  a  paper  presented  by  Dr.  J.  B.  Russell  to  the  Philosoph- 
ical Society  of  Glasgow  in  1888^  there  appear  the  results  of 
studies  made  with  the  view  of  determining  in  how  far  an 
excessive  density  in  population  affected  the  death-rate  of  that 
city  and  to  what  extent  such  crowding  was  answerable  for 
the  prevalence  of  diseases  of  a  special  character.  The  author 
demonstrates  that  the  death-rate  in  Glasgow  is  greatest  in 
those  districts  in  which  the  greatest  number  of  individuals  are 
domiciled  in  the  smallest  cubic  space,  and  that  there  is  a 
gradual  decrease  in  the  death-rate  as  the  ratio  between  living- 
space  and  number  of  inhabitants  becomes  greater  (Table  VIIL). 

'  Consult  35th  Report  of  the  Registrar  General  of  England  (1875)  ;  Sup- 
plement, pp.  clviii,  clix. 

^  On  the  "Ticketed  Houses"  of  Glasgow,  with  an  Interrogation  of  the 
Facts  for  Guidance  toward  the  Amelioration  of  the  Lives  of  Occupants.  By  J. 
B.  Russell,  B.  A.,  M.  D.,  LL.D.,  Proc.  Phil.  Soc,  1888-89,  vol.  xx.,  pp.  i 
to  24  inclu. 


42 


HYGIENE    OE   TRANSMISSIBLE   DISEASES. 


Table  VIII. — The  folloiving  table,  eompilcd  by  Dr.  Russell, 
sho7vs  tJie  distribution  of  population  and  deaths  in  houses  of 
various  sizes  : 


Size  of  House. 


Pupuhition.      Deaths. 


One  room       134,728 

Two     rooms 243,691 


Three 

Four        "  .... 

Five  rooms  and  upward 

Institutions 

Un  traced 

Whole  city     .    .    . 


86,956 

32,742 

38,647 

6,531 


543,295 


3,636 
6,325 

1,747 
581 
434 
427 
289 

13,439 


Percentage  of 

Population. 

Deaths. 

24.7 

27.0 

44-7 

47.0 

16.0 

13.0 

6.1 

4-3 

7-1 

3-3 

1.4 

3-2 

2.2 

1 00.0 

1 00.0 

As  to  the  character  of  diseases  most  prevalent  among  the 
occupants  of  these  several  classes  of  domiciles,  the  same 
author  found  that  zymotic,  nervous,  and  nutritive  diseases  of 
children,  accidents  and  syphilis  in  children,  pulmonary  and 
miscellaneous  diseases  occurred  in  the  relative  degrees  of 
frequency  indicated  by  the  following  table  and  chart  (Table 
IX.,  Chart    i). 

Table  IX. — Showing  death-rates  per  100,000  from  cef'tain  classes 
of  diseases  in  various  size  houses  {Russell^  : 


One  and        Three  and 

two  room        four  room 

houses.  houses. 


Zymotic  di.seases 478 

Acute  diseases  of  the  lungs   (including   "|  p 

consumption) )  "  -^ 

Nervous  diseases  and  diseases  of  nutri-    ^  o 

tion  in  children /  ^ 

Accidents  and  syphilis  in  children      .    .    .  i  32 

Miscellaneous  unclassified  diseases     .    .    .  j  799 

All  causes 2774 


It  would  be  a  mistake,  however,  to  consider  that  the 
parallelism  between  the  various  densities  of  population  and 
increase  of  death-rate  observed  in  Glasgow  forms  a  basis  for 
an  infallible  generalization  that  would  be  applicable  to  the 
entire  population  of  all  countries  ;  for  in  a  census  of  28  large 
towns  in  England  and  in  Wales  (ending  Januaiy  i,  1897)  it 
was  impossible  to  detect  such  constancy  between  density  of 


THE    CAUSATION   OF  DISEASE. 


43 


population  and  death-rate,  though  the  communities  studied 
were  embraced  between  the  extremes  represented  by  Hud- 
dersfield,  with  a  population  of  90,034,  a  density  of  8.6  persons 
per  acre,  a  birth-rate  of  27.7,  and  a  death-rate  of  from  19.6  to 
23.0  per  1000,  and  Liverpool,  with  a  population  of  592,991,  a 
density  of  113.8  persons  per  acre,  a  birth-rate  of  31.2,  and  a 
death-rate  of  from  23.7  to  25.2  per   1000. 

Chart  i. — Showing  incidence  of  certain  classes  of  diseases  among 
occupants  of  various  size  houses  {^Russell ). 


a  b  c 

a.  One  and  two  room  nouses ;  b,  three  and  four  room  houses ;  c,  five  rooms 
and  upward;  (i)  zymotic  diseases;  (2)  nervous  and  other  diseases  special  to 
children;  (3)  accidents  and  syphihs  in  children;  (4)  diseases  of  the  lungs;  {5) 
miscellaneous  diseases. 

Similarly  in  the  United  States  ^  we  find  the  density  of 
population,  as  expressed  by  persons  per  acre,  to  bear  no  con- 
stant relation  to  the  death-rates  in  50  large  cities  in  this 
country,  from  which  the  statistics  were  compiled.     The  data 

1  See  Eleventh  Census  of  the  United  States,  volume  on  Social  Statistics  of 
Cities.      Diagram  3,  pp.  8  to   12. 


44  HYGIENE    OF  TRANSMISSIBLE   DISEASES. 

referred  to  were  embraced  between  the  extremes  represented 
by  New  York  cit}',  with  58  persons  per  acre  and  a  death-rate 
of  28.63  per  1000  of  population,  and  Fall  River,  Mass.,  with  4 
persons  per  acre  and  a  death-rate  of  24.84  per  looo  of  popu- 
lation. Though  a  diminution  in  the  number  of  persons  per 
acre  from  New  York  city  through  the  list  to  Fall  River, 
Mass.,  was  constant,  still  the  death-rates  observed  in  the  cities 
of  the  table  that  fall  between  these  extremes  were  most  irreg- 
ular, 6  being  practically  equivalent  to  that  of  New  York  city, 
and  34  being  less  than  that  of  Fall  River,  Mass. 

It  must  be  said,  however,  that  the  data  obtained  from  the 
"]%  cities,  including  2'^  in  England  and  50  in  this  country,  do 
not  of  necessity  vitiate  the  results  of  Dr.  Russell's  studies,  for 
"  the  statement  of  the  average  density  of  the  population  of  a 
city  by  no  means  indicates  the  amount  of  overcrowding  which 
may  exist  in  certain  parts  of  it  "  (Billings). 

It  does  not  seem  improbable  that  had  investigations  been 
conducted  in  any  or  all  of  these  78  cities  along  identically  the 
same  lines  as  those  employed  by  Dr.  Russell,  results  corre- 
sponding with  those  obtained  by  him  could  have  been  secured 
for  people  living  in  sections  of  these  cities  under  conditions 
of  overcrowding  such  as  were  observed  and  studied  in 
Glasgow. 

The  most  important  factors  in  favor  of  an  increasing  death- 
rate,  under  conditions  of  high  aggregation  of  people,  are  the 
generally  unhygienic  conditions  under  which  the  population 
exists,  including  filth,  bad  air,  poor  and  insufficient  food,  in- 
adequate clothing,  deficient  shelter,  increased  opportunities  for 
direct  infection,  and  the  manifold,  though  potent,  influences 
that  are  concomitant  with  poverty.  The  dissemination  of 
infection  is  in  inverse  ratio  to  the  distance  between  individuals 
congregated  together  in  a  habitation  ;  the  greater  the  distance 
the  less,  the  less  the  distance  the  greater  the  liability  for  in- 
fection to  spread. 

"  The  more  crowded  a  community,  the  greater,  speaking 
generally,  is  the  amount  of  abject  want,  of  filth,  of  crime,  of 
drunkenness,  and  of  other  excesses,  the  more  keen  the  com- 
petition and  the  more  feverish  and  exhausting  the  conditions 


THE    CAUSATION  OF   DISEASE.  45 

of  life.  Moreover,  and  perhaps  more  than  all,  it  is  in  these 
crowded  communities  that  almost  all  the  most  dangerous 
and  unhealthy  industries  are  carried  on.  It  is  not  so  much 
the  aggregation  itself,  as  it  is  these  other  factors  which  are 
associated  with  aggregation,  that  produce  the  high  mortality 
of  our  great  towns,  or  other  thickly  populated  areas  "  (Ogle). 

Heredity — In  predisposing  to  disease  heredity  manifests 
its  influence  more  through  the  transmission  of  a  peculiar 
habit  of  body  than  by  the  transmission  of  disease  itself  In 
the  modern  sense,  inherited  predisposition  to  disease  implies 
a  congenital  condition  that  is  pecuHar  to  the  idioplasm  of  the 
individuals  of  certain  families,  a  condition  that  inclines  them 
to  this  or  that  particular  form  of  malady.  For  instance,  in 
some  families  we  observe  a  peculiar  tendency  to  nervous  dis- 
eases, as  to  epilepsy,  or  insanity  ;  in  others  to  cancers  and 
tumors  ;  in  others  to  scrofula,  tabes,  and  other  tubercular 
manifestations.  The  rheumatic  and  gouty  diatheses  and 
syphilis  belong  also  to  this  category.  Again,  families  are 
encountered  that  are  endowed  with  a  marked  predisposition 
to  acute  diseases,  while  in  others  there  is  an  equally  marked 
resistance  to  them.  In  short,  the  inheritance  of  a  tendency 
to  or  immunity  from  disease  is  due  fundamentally  to  the  same 
processes  through  which  peculiarities  of  a  physical,  moral,  or 
mental  nature  are  transmitted. 

The  question  concerning  the  direct  transmission  of  disease 
from  parents  to  offspring  is  oiic  over  which  there  has  been  a 
great  deal  of  controversy.  With  regard  to  certain  diseases,  such 
as  syphilis  and  some  of  the  acute  infections,  there  can  be  no 
doubt  that  such  a  transmission  occurs  ;  but  in  connection 
with  tuberculosis  there  is  .still  more  or  less  disagreement  of 
opinion.  The  weight  of  evidence  contra-indicates  the  prob- 
ability of  tuberculosis  being  often  directly  inherited,  and  while 
it  is  impossible  to  deny  the  intra-uterine  existence  of  the  dis- 
ease, yet  hereditary  tuberculosis  must  be  looked  upon  as  a 
rarity.  The  part  played  by  heredity  in  the  dissemination  of 
this  disease  is  more  often  observed  in  the  transmission  of  a 
generally  enfeebled  constitution,  with  a  special  predisposition 
to  this  particular  form  of  infection.     It  is  manifest  that  through 


46  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

the  intimacy  existintj  between  tubercular  patients,  particularly 
mothers,  and  their  offspring  that  are  congenitally  endowed 
with  this  predisposition,  there  are  abundant  opportunities  for 
accidental  infection.  Fagge  calls  attention  to  the  frequent 
impossibility  of  distinguishing  between  hereditary  and  acci- 
dentally-acquired tuberculosis.  On  the  other  hand,  Baum- 
garten  favors  the  opinion  that  tuberculosis  is  frequently  in- 
herited, and  that  the  virus  lies  dormant  (is  held  in  check) 
until  after  the  period  of  active,  infantile  tissue-development, 
when  it  exhibits  its  pathogenic  properties. 

It  is  appropriate  at  this  place  to  refer  to  the  relative  insus- 
ceptibility to  disease  that  is  occasionally  observed,  and  to 
repeat  that  this  peculiarity,  like  predisposition  to  disease,  is  a 
property  that  is  inherent  to  the  germ-plasm  of  the  individuals 
and  their  progenitors  thus  endowed.  It  is  not  probable  that 
the  comparative  immunity  from,  or  the  increased  resistance 
to,  a  disease  that  is  conferred  upon  an  individual  by  a  single 
non-fatal  attack  of  that  disease  is  transmitted  to  his  offspring, 
any  more  than  are  the  numerous  other  quickly  acquired  traits 
or  characteristics.  At  least  we  have  no  evidence  in  favor  of 
such  a  view.  Important  light  has  been  shed  upon  this  phase 
of  our  subject  by  the  brilliant  researches  of  Ehrlich  and  cer- 
tain of  his  followers  in  these  interesting  investigations.  Ehrlich 
has  shown  that  acquired  immunity  from  poisons  that  are  in 
many  respects  analogous  to  those  concerned  in  the  morbid 
phenomena  of  infectious  diseases  is  not  transmissible  from 
parents  to  offspring,  in  the  way  that  physical  and  mental  pe- 
culiarities are  handed  down  ;  in  fact,  they  are  not  inherited  at 
all,  but  that  for  a  temporary  period  during  nursing  the  immune 
mother  conveys  to  the  suckling,  through  the  milk,  a  substance 
that  serves  to  protect  the  offspring  from  the  disease  from 
which  the  mother  is  immune.  This  protection  is  not  perma- 
nent, but  ceases  with,  or  a  veiy  short  time  after,  the  cessation 
of  nursing.  Moreover,  this  protection  is  maternal,  the  father 
taking  no  part  in  it — a  state  of  affairs  contrary  to  what  we 
know  to  be  the  case  with  regard  to  the  inheritance  of  physical, 
mental,  and  moral  characteri.stics. 

It  is  more  than  probable  that  the  observation  of  Krhlich, 


THE    CAUSATION   OF  DISEASE. 


47 


made  upon  animals  (mice),  may  have  an  important  bearing 
upon  the  phenomenon  in  human  beings. 

Season. — The  fact  that  certain  groups  of  diseases  are  most 
prevalent  at  definite  seasons  of  the  year  indicates  a  predis- 
posing relation  between  the  characteristics  of  those  seasons 
and  such  diseases. 


Chart  2. — Showing  the  monthly  fluctuations  in  the  death-rates  from 
diseases  of  the  respiratory  system  in  Nezv  York  City  and  in  Balti- 
rnore. 


Months 

NEW  YORK  CITY 

BALTIMORE 

30                 20                  10 

10           20           30 

1 

Jviiie 

July 

' 

m^i     ^^vigvist 

fl 

SepteiTtilDer 

1 

Octolaer 

USTovem.'ber 

1 

DecemlDer 

■ 

[^■1 

Jaiiuary- 

■■ 

J 

IT'elaru.a.ry 

1 

Vi^B 

IN^TarcK 

1 

1 

A.pril 

■ 

1 

May 

n 

It  is  a  matter  of  common  observation  that  catarrhal  dis- 
eases and,  in  general,  those  of  the  respiratory  system  are 
more  frequent  during  the  months  of  low  temperature  and 
excessive  moisture  than  at  other  times  in  the  year  (see  Chart 
2).  Whether  this  is  due  to  atmospheric  conditions  alone,  or 
to  those  in  conjunction  with  the  evil  effects  of  crowding 
together  in  badly  ventilated  rooms,  kept  closed  for  purposes 
of  warmth,  it  is  difficult  to  say  ;  but  it  would  appear  more 
reasonable  to  consider  both  influences  together  as  the  predis- 
posing conditions. 

During  the  heated  months  the  diseases  that  are  most  prev- 


48 


HYGIENE    OE   T/^.-lXSMISS/BLE   DISEASES. 


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'— ' 

THE    CAUSATION   OF  DISEASE. 


49 


alent  are  those  connected  with  the  digestive  system.  This  is 
especially  the  case  with  young  children,  and  particularly  those 
whose  food  consists  of  materials  that  readily  undergo  fer- 
mentation under  the  favorable  conditions  of  temperature 
afforded  by  the  season. 

In  Chart  3  is  shown  the  relative  monthly  fluctuation  in  the 
death-rate  from  diarrheal  diseases  in  the  cities  of  New  York 
and  Baltimore  for  the  six  years  ending  May  31,  1890,  and  it 
will  be  seen  that  by  far  the  greater  proportion  of  deaths  occur 
in  the  period  of  excessive  heat — viz.,  July. 

The  periods  of  greatest  vegetable  activity,  with  the  subse- 
quent period  of  decline,  are  those  in  which  malarial  diseases 
appear  most  conspicuously. 

Chart  4. — Showing  by  viotiths  the  seasonal  variation  in  the  occurrence 
of  malarial  fever  (arranged  from  statistics  of  Thayer  and  Hewetsori). 


The  foregoing  diagram  (Chart  4),  arranged  from  the  statis- 
tics of  Thayer  and  Hewetson  upon  malaria  in  Baltimore, 
gives  an  accurate  idea  of  the  seasonal  distribution  of  the  cases 
of  this  disease  : 


For  reasons  that  cannot  be  satisfactorily  explained,  typhoid 
fever  is  a  disease  of  early  autumn.     While  occurring  to  some 
4 


50 


HYGIENE    OF  TRANSMISSIBLE  DISEASES. 


extent  throughout  the  year,  the  period  of  greatest  disease- 
and  death-rates  is  usually  during  the  months  of  August, 
September,  and  October  (see  Chart  5).^ 

Chart   5. — Showing  by  iiiotiihs  the  seasonal  variation  in  the  occur- 
rejice  of  typhoid  fever  {arranged  from  statistics  of  Osier). 


The  acute  exanthemata  are  much  more  prevalent  from  the 
late  autumn  to  the  early  spring  than  at  other  times  in  the 
year  (see  Chart  6).  Aside  from  seasonal  influence  per  se,  it 
must  be  borne  in  mind  that  these  are  the  periods  in  which  the 
opportunities  for  infection  are  greatest — i.  c,  they  comprise 
the  months  during  which  children  of  school  age  are  at  school, 
and  in  more  or  less  intimate  contact  with  one  another. 

For  the  six  years  ending  May  31,  1890,  the  highest  average 
death-rate  for  all  ages  in  New  York,  Brooklyn,  Boston,  and 
Philadelphia  occurred  in  the  month  of  July,  and  for  children 
under  five  years  of  age  very  much  the  higliest  death-rate  was 
in  this  month.  It  is  because  of  this  striking  increase  in  infant 
mortality  during  the  hot  weather  that  the  death-rates  of  all 
our  large  cities  are  uniformly  high  in  July  and  August. 

'  Compiled  from  Osier's  "General  Analysis  and  Summary  of  229  Cases 
of  Typhoid  Fever,"  folins  Hopkins  Hospital  Reports,  vol.  iv..  No.  I. 


THE    CAUSATION  OF  DISEASE. 


51 


With  regard  to  seasonal  influence,  we  find  that  the  dis- 
eases which  are  conspicuously  prevalent  during  the  colder 
months  are  those  that  are  most  common  in  countries  of 
high  latitude — i.  e.,  having  the  greatest  amount  of  cold  and 
wet  weather ;  while  those  common  to  our  months  of  high 
temperature  are  closely  allied  to  those  most  frequent  in 
tropical  climates. 

Chart  6. — Showing  by  months  the  average  relative  proportions  of 
deaths  from  diphtheria  and  scarlatina  in  Philadelphia,  for  the  six 
years  ending  May  ji,  i8go.  Rates  are  per  1000  deaths  from  all 
causes. 


Months 

Diphtheria 

Scarlatina 

30         20          10 

10         20         30 

•J-u.xie           ^^H 

■1 

Jul;^          ^^H 

r 

1 

^uj^ust      ^^1 

1 

Septemlaer  ^| 

October      ^^| 

jS"oveml3er  ^^H 

1 

DeceiiiTaer  m 

1 

Jaiiu.arj'-    ^^^ 

February   ^^H 

1 

IVCarcli       ^1 

A.pril         ^^9 

IVEa^^         HI 

The  Bxciting  Causes  of  Disease. — Employing  the 
word  disease  in  its  broad  sense,  as  comprising  all  departures 
from  normal  physiological  function  and  all  defects  of  anatom- 
ical structure,  we  recognize  a  group  of  chemical,  physical, 
and  vital  agents  that  may  be  more  or  less  directly  concerned 
in  its  causation. 

The  term  "  direct  "  or  "  exciting,"  as  applied  to  the  causes 
of  disease,  is  limited  to  those  chemical,  physical,  and  mechan- 
ical agencies  that  are  capable  of  inducing  abnormal  conditions 
of  the  organism  without  the  intervention  of  any  other  modi- 
fying factors  ;  and  while  this  term  is  similarly  applied  to  the 


52  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

vital  agents  that  are  instrumental  in  inducing  definite  patho- 
logical conditions  and  clinical  manifestations,  it  must  be  borne 
in  mind  that  without  the  intervention  of  predisposing  condi- 
tions it  is  improbable  that  the  vital  causes  of  disease  are  of 
themselves  capable,  at  any  and  all  times,  of  performing  their 
characteristic  pathogenic  functions. 

For  the  manifestation  of  their  particular  pathogenic  powers 
the  vital  agents  require  that  the  organism  upon  which  they 
are  to  act  is  either  by  nature  susceptible  to  their  influence,  or 
is  rendered  so  through  the  action  of  the  many  detrimental 
agencies  that  serve  to  diminish  resistance  and  predispose  to 
disease. 

The  vital  factors,  while  classed  as  the  direct  causes  of  dis- 
eases, cannot  therefore  be  considered  as  standing,  independent 
and  alone,  in  causal  relation  to  the  processes  ;  and  while  they 
are,  in  the  strict  sense  of  the  word,  the  direct  and  only  excit- 
ing causes  of  certain  specific  phenomena,  they  still  require 
special  conditions  of  the  body  that  are  favorable  to  their 
activity  and  development.  These  conditions  usually  depend 
for  their  existence  upon  one  or  more  of  the  influences  already 
referred  to  as  predisposing. 

Chemical  Causes. — The  direct  chemical  causes  of  disease 
may  be  divided  into  those  having  their  origin  outside  the  body 
(ectogenous),  and  those  that  are  created  within  the  body 
(endogenous)  as  a  result  of  malnutrition,  malfermentation, 
and  other  defects  of  metabolism  and  physiological  function. 
Those  originating  without  the  body  comprise  the  numerous 
organic  and  inorganic  substances  of  an  irritating  or  poisonous 
nature  that  possess  the  property  of  causing  abnormal  local 
and  con.stitutional  conditions  in  those  exposed  to  their  influ- 
ence. The  commonest  of  them  are  the  various  hurtful  sub- 
stances used  in  certain  trades,  as,  for  example,  phosphorus, 
ar.senic,  chromic,  and  oxalic  acids,  mercury  and  its  salts,  and 
certain  of  the  irritating  coal-tar  products.  To  this  category 
belong  certain  drugs,  such  as  opium,  chloral,  cocain,  alcohol, 
etc.,  which  are  frequently  indulged  in  because  of  their  agree- 
able effects.  The  poisons  of  particular  plants,  as  of  rhus 
toxicodendron,  or  atropa  belladonna^  of  hyoscyani7is  niger,  of 


THE    CAUSATION  OF  DISEASE.  53 

riciiiiis,  of  croion  tiglmin,  and  many  others,  possess  likewise 
the  power  of  directly  inducing  abnormal  local  and  general 
conditions.  To  this  list  must  be  added  the  poisons  of  venom- 
ous reptiles. 

Those  originating  within  the  body  (endogenous)  comprise 
a  group  of  compounds  of  whose  nature  we  are  as  yet  but  ill- 
informed.  They  represent,  most  Kkely,  intermediate  products 
in  the  processes  of  nutrition  which,  through  physiological  de- 
fects, are  not  completely  elaborated,  and  which  in  this  state 
and  under  the  existing  condition  of  physiological  enfeeble- 
ment  are  endowed  with  poisonous  peculiarities  ;  also,  the  ordi- 
nary end-products  of  tissue-activity  that  have  accumulated 
within  the  system  as  a  result  of  structural  lesions  of  the 
secretory  and  excretory  organs  ;  and  equally  as  important 
as  either  of  the  preceding,  the  toxic  products  of  malfer- 
mentations   often  in  operation  within  the  alimentary  tract. 

Physical  and  Mechanical  Causes. — The  most  frequent 
direct  physical  causes  of  disease  are  excessive  heat,  cold,  and 
moisture,  while  the  mechanical  causes  are  both  predisposing 
and,  in  the  case  of  accident,  exciting. 

Vital  Causes. — By  the  term  vital  causes  of  diseases  are 
meant  those  living  animal  and  vegetable  parasites  which, 
having  gained  access  to  the  body,  produce,  as  a  result  of 
their  development  under  favorable  circumstances,  tissue- 
lesions  that  terminate  in  disturbance  of  important  vital 
functions,  and  frequently  in  local  or  complete  death  of  the 
host  in  which  they  are  developing. 

The  disturbances  that  result  from  the  invasion  of  the  body 
by  animal  parasites  vary  with  the  character,  mode  of  nutri- 
tion, life  cycle,  and  location  of  the  invading  organism.  In  the 
one  case  they  may  manifest  themselves  through  symptoms 
that  point  more  particularly  to  the  circulating  blood,  in 
another  by  more  or  less  grave  disturbances  of  nutrition. 
Again,  nervous  irritability,  at  times  extreme,  will  be  observed. 
In  special  instances  marked  and  persistent  diarrhea  results  ; 
while  with  other  forms  of  animal  parasites  the  results  of  their 
presence  appear  to  be  due  mainly  to  the  mechanical  irritation 


54  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

caused  by  their  lodgement  in  the  internal  viscera  and  in  the 
organs  of  the  special  senses. 

Thus,  for  instance,  we  observe  the  nutritive  disturbances, 
the  emaciation  and  the  nervous  accompaniments  of  the  in- 
vasion of  the  body  by  the  teniae  ;  the  anemia,  often  extreme, 
that  results  from  the  activity  of  the  host  of  blood-sucking 
strongylidai  which  attach  themselves  to  the  mucous  mem- 
brane of  the  upper  part  of  the  small  intestine  in  the  disease 
ankylostomiasis  ;  the  alarming  symptoms  that  are  associated 
with  the  occasional  obstruction  of  the  larger  lymphatic  chan- 
nels by  filaria  sanguinis  honiinis  or  its  embryos ;  the  suppu- 
ration and  ulceration  consequent  upon  the  lodgement  of  the 
guinea-worm  in  the  subcutaneous  tissues  ;  and  the  disturbance 
of  function  that  occurs  from  the  presence  of  cysticerci  in  the 
central  nervous  system  and  organs  of  special  sense. 

As  we  shall  learn  later,  the  niodiis  operandi  of  disease-pro- 
duction by  animal  parasites  differs  veiy  materially  from  that 
of  the  vegetable  micro-organism. 

Bacteria. — For  the  human  being,  and  many  lower  animals, 
the  most  important  of  the  vegetable  parasites  that  are  directly 
concerned  in  the  production  of  disease  are  the  bacteria. 

Bacteria  are  the  unicellular  micro-organisms  that  mul- 
tiply by  the  simple  process  of  transverse  division.  They  are 
concerned  in  a  great  many  phenomena  other  than  that  of 
disease-production.  The  majority  of  them  are  benefactors 
rather  than  enemies  to  mankind.  They  are  nature's  scaven- 
gers, being  the  underlying  cause  of  all  processes  of  disin- 
tegration and  decomposition  through  which  dead  organic 
matter  is  converted  into  simpler  compounds  suitable  for  the 
nutrition  of  more  highly  organized  vegetables.  It  is  largely 
through  the  activities  of  bacteria  that  the  equilibrium  of  the 
chemical  composition  of  the  atmosphere  is  maintained,  for 
the  amount  of  carbonic  acid  thrown  into  the  atmosphere  as  a 
result  of  animal  respiration  alone  is  insufficient  to  meet  the 
demands  of  the  growing  chlorophyl  plants.  The  deficit  is 
made  up  through  the  activities  of  bacteria  in  converting 
dead  organic  matter  into  this  gas  as  one  of  the  end- 
products    of  tlie    process   of   decomposition.       It   is   to    the 


THE   CAUSATION  OF  DISEASE.  55 

activities  of  bacteria  that  commerce  is  indebted  for  important 
products — viz.,  for  certain  of  the  organic  acids,  and  for  prac- 
tically its  entire  supply  of  saltpetre.  In  agriculture  their  role 
is  no  less  important.  They  are  the  instruments  through 
which  are  perfected  the  processes  in  operation  in  nature's - 
great  laboratory — the  upper  layers  of  the  soil — which  are 
destined  to  supply  the  food  for  growing  crops.  Through 
their  association  the  leguminous  plants  are  enabled  to  obtain 
a  portion  of  their  supply  of  nitrogen  from  the  gaseous 
nitrogen  of  the  air — a  phenomenon  which  was  until  com- 
paratively recently  supposed  to  be  impossible,  the  nitrogen 
of  the  atmosphere  having  always  been  considered  to  be  of 
no  biological  significance. 

Since  the  discovery  of  bacteria  by  Leeuwenhoek  in  1668- 
1675,  our  knowledge  of  these  parasites  has  continuously 
developed  until  we  are  now  pretty  familiar  with  the  majority 
of  their  important  peculiarities. 

In  addition  to  the  functions  of  bacteria,  mentioned  above, 
there  remains  to  be  considered  their  role  in  the  production  of 
disease.  Diseases  that  depend  for  their  existence  upon  the 
presence  of  bacteria  in  the  tissues  are  known  as  infections 
diseases,  and  the  process  by  which  they  are  caused  is  known 
as  infection.  As  here  employed,  the  term  infection  refers 
more  especially  "  to  the  morbific  agents  causing  disease,  and 
implies  nothing  as  to  the  mode  of  transmission  of  these 
agents."  A  contagious  disease  is  one  transmissible  from 
individual  to  individual  by  immediate  or  direct  contact.  Con- 
tagious diseases,  like  infectious  diseases,  are  dependent  upon 
the  activities  of  vital  pathogenic  agents  in  the  tissues,  though 
in  the  case  of  the  majority  of  the  commonest  contagious 
maladies,  like  small-pox,  measles,  scarlatina,  and  rotheln,  the 
nature  of  these  agents  is  unknown.  Miasmatic  diseases  result 
from  the  invasion  of  infectious  agents  from  without,  which 
cannot  always  be  traced  either  directly  or  indirectly  to  some 
other  case  of  the  same  disease.  Malaria  may  be  regarded  as 
a  typical  miasmatic  disease. 

It  is  evident  that  the  term  infectious,  as  referring  to  the 


56  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

causation  of  disease,  is  broader  than  the  term  contagious, 
Avhich  relates  only  to  the  manner  of  transmission. 

As  the  term  is  ordinarily  understood  mfectioiis  diseases,  as 
distinct  from  the  contagious,  are  disseminated  indirectly — /.  e., 
in  a  roundabout  way,  by  means  of  the  water,  the  soil,  or  the 
food  to  which  the  mcfrbific  agents  from  a  case  of  infectious 
disease  have  gained  access  ;  while  the  contagious  diseases 
spread,  as  stated,  by  direct  contact  from  a  sick  to  a  healthy 
individual.  The  miasmatic  diseases  follow  the  rule  given  for 
infectious  diseases  in  general,  though  they  are  not  always 
dependent  upon  pre-existing  cases  of  the  disease.  It  is  mani- 
fest from  what  has  been  said,  that  all  contagious  diseases  are 
infectious,  but  that  many  of  the  infectious  diseases  are  not 
contagious. 

Typhoid  fever,  cholera,  and  the  common  suppurations  are 
examples  of  non-contagious,  infectious  diseases. 

Erysipelas,  pneumonia,  tuberculosis,  glanders,  and  diph- 
theria, though  not  usually  contagious,  may  become  so  under 
favorable  conditions.  Small-pox,  measles,  scarlatina,  rotheln, 
mumps,  and  varicella  are  infectious  diseases  that  are  notably 
contagious. 

"  Whether  or  not  an  infectious  disease  is  contagious  in  the 
ordinary  sense  depends  upon  the  nature  of  the  infectious 
agent,  and  especially  upon  the  manner  of  its  elimination  from 
and  reception  by  the  body  "  (Welch). 

The  proof  necessaiy  to  demon.strate  a  causal  relation 
between  a  given  bacterial  species  and  a  disease  is  embodied 
in  the  postulates  formulated  by  Koch,  to  the  effect : 

1.  That  the  micro-organism  under  consideration  shall 
always  be  found  in  the  diseased  tissues  in  such  numbers,  and 
in  such  relations  to  these  tissues,  that  they  can  reasonably  be 
assigned  an  etiological  relation  to  the  process. 

2.  That  the  micro-organism  shall  be  isolated  from  the 
disea.scd  tissue  in  pure  cultures. 

3.  That  the  pure  cultures  of  the  micro-organism  shall  be 
capable,  when  inoculated  into  susceptible  animals,  of  repro- 
ducing pathological  lesions  identical  with  those  from  which  it 
was  originally  isolated. 


THE    CAUSATION   OF  DISEASE.  5/ 

4.  That  the  micro-organism  shall  be  found  in  the  lesions 
produced  by  inoculation 

It  has  been  suggested  that  to  these  requirements  be  added  : 
"  That  the  organism  be  not  found  in  other  pathological  con- 
ditions ;  "  and  "  that  it  is  not  one  of  the  harmless  commensal 
species  that  are  found  in  the  intestine  or  on  the  skin."  The 
inadvisability  of  introducing  the  latter  two  requirements  is 
at  once  apparent,  as  we  know  that  several  pathogenic  species, 
particularly  those  concerned  in  the  causation  of  suppurative 
processes,  and  many  of  those  grouped  as  septicemic  bacteria, 
are  at  times  concerned  in  the  production  of  pathological 
lesions  that  differ  very  materially  the  one  from  the  other. 
For  instance,  streptococcus  pyogenes  may  under  one  set 
of  conditions  cause  erysipelas,  under  another  phlegmonous 
inflammation ;  micrococcus  lanceolatiis  is  known  to  be  the 
cause  of  acute  lobar  pneumonia,  of  acute  endo-  and  peri- 
carditis, of  peritonitis,  of  cerebrospinal  meningitis,  of  suppura- 
tions of  the  middle  ear,  and  of  circumscribed  abscess-forma- 
tion. The  members  of  the  group  of  hemorrhagic  septicemia 
bacteria,  while  usually  instrumental  in  producing  an  acute 
general  infection,  may  under  special  circumstances  cause  a 
condition  that  is  conspicuous  for  its  local  manifestations,  and 
the  extent  of  general  infection  may  be  very  insignificant. 

With  regard  to  the  so-called  "  harmless  commensal " 
species,  we  know  that  under  various  circumstances  they  may 
exhibit  pathogenic  properties.  A  conspicuous  illustration  is 
found  in  the  common  bacillus  of  the  colon  {bacillus  coli 
connnunis) — an  organism  present  in  the  colon  of  all  human 
beings  and  of  many  lower  animals.  Under  ordinary  circum- 
stances these  organisms  exist  as  harmless  saprophytes,  but 
under  conditions  that  bring  about  lesions  of  the  intestinal 
mucous  membrane,  or  those  causing  general  reduction  of 
vital  resistance,  this  organism  may  exhibit  disease-producing 
properties. 

In  the  mouth-cavity  of  a  very  large  proportion  of  normal 
human  beings  micrococcus  lanceolatus  (pneumococcus)  is 
found.  This  organism,  like  the  one  just  mention&d,  may 
prove  to  be  of  no  danger  to  the  host  in  which  it  is  living,  or 


58  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

it  may,  through  the  aid  of  predisposing  factors,  become  the 
cause  of  a  variety  of  pathological  conditions. 

In  the  skin  of  many  individuals  the  pyogenic  cocci  may  be 
demonstrated.  These  too  may  continue  to  exist  as  innocent 
saprophytes,  or  they  may,  under  favorable  conditions,  exhibit 
their  disease-producing  powers. 

We  see  that  a  given  species  may,  with  varying  conditions, 
cause  lesions  of  a  dissimilar  kind  ;  and  we  also  see  that  the 
so-called  "  innocent,  commensal  "  species  may  at  times  take 
on  pathogenic  properties. 

With  regard  to  the  postulates  of  Koch,  it  is  manifest  that 
their  fulfilment  is  possible  only  in  a  limited  number  of  cases. 

Some  of  the  most  important  diseases  that  are  known  clin- 
ically to  be  of  an  infectious  nature  have  thus  far  eluded  all 
efforts  to  discover  their  causative  factors.  In  others  micro- 
organisms may  be  constantly  found,  and  these  micro-organ- 
isms may  be  exclusively  found  in  these  diseases,  though  no 
success  has  followed  the  efforts  to  isolate  and  cultivate  them. 
In  still  other  groups  definite  bacterial  species  may  be  found, 
isolated  and  cultivated,  and  yet  the  reproduction  of  the  dis- 
ease by  inoculation  into  lower  animals  has  either  been  impos- 
sible, or  only  in  part  satisfactory,  owing  to  the  difficulty  of 
faithfully  reproducing  in  animals  used  for  inoculation  the 
clinical  symptoms  and  pathological  lesions,  by  which  the  dis- 
eases from  which  the  bacteria  were  isolated  are  characterized 
in  man. 

There  are  many  important  diseases  to  which  mankind  is 
liable  that  do  not  occur  spontaneously  and  cannot  be  pro- 
duced in  animals  that  are  used  for  purposes  of  experimentation. 
There  is  no  evidence  that  animals  ever  suffer  spontaneously 
from  such  diseases  as  typhoid  fever,  Asiatic  cholera,  leprosy, 
syphilis,  malaria,  yellow  fever,  small-pox,  measles,  etc.,  and 
it  is  seen  to  be  in  the  main  impossible,  even  in  those  animals 
that  are  in  general  most  susceptible  to  infection,  to  produce 
by  inoculation  clinical  and  pathological  manifestations  that  are 
a  correct  reproduction  of  those  that  characterize  these  dis- 
eases in  human  beings. 

For  the  group  of  septicemias  that  occur  in  animals,  such 


THE    CAUSATION  OF  DISEASE.  59 

as  chicken  cholera,  rabbit  septicemia,  anthrax,  and  mouse 
septicemia  ;  for  certain  suppurative  processes  ;  for  diphtheria, 
for  glanders,  for  gonorrhea,  and  for  tuberculosis,  the  proof  is 
conclusive,  and  all  the  requirements  have  been  met ;  but  for 
cholera,  typhoid  fever,  malaria,  and  leprosy,  and  for  amoebic 
dysentery,  and  certain  other  protozoal  diseases,  the  postulates 
of  Koch  have  only  in  part  been  fulfilled.  It  should  be  said, 
with  regard  to  Asiatic  cholera  and  typhoid  fever,  that  by  par- 
ticular methods  of  experimentation  pathological  conditions 
somewhat  analogous  to  those  seen  in  man  have  been  pro- 
duced, but  in  general  the  results  thus  obtained  are  not  fairly 
comparable,  either  etiologically,  pathologically,  or  clinically, 
with  those  observed  in  human  beings  affected  with  these  mal- 
adies. In  one  or  two  instances  cholera  has  occurred  in 
human  beings  who  have  purposely  or  accidentally  swallowed 
cultures  of  the  cholera  spirillum. 

There  are  a  number  of  infectious  diseases,  including  those 
dependent  upon  the  presence  of  protozoa  in  the  tissues,  in 
which  only  the  first  of  the  requisite  proofs  has  been  estab- 
lished. In  these  diseases  there  are  constantly  and  exclusively 
present  micro-organisms  that  are  capable  of  microscopical  de- 
monstration, but  of  which  none  have  been  isolated  in  culture, 
and  the  diseases  have  not  been  satisfactorily  reproduced  in 
animals.  The  most  important  of  the  group  are  malaria, 
amoebic  dysentery,  relapsing  fever,  leprosy,  and,  possibly, 
syphilis.  The  majority  of  the  commonest  infectious  diseases 
have  eluded  all  efforts  to  discover  their  specific  causative 
agent.  Of  these  may  be  mentioned  yellow  fever,  measles, 
scarlet  fever,  small-pox,  varicella,  mumps,  dengue,  and  ty- 
phus fever. 

As  regards  their  life-processes,  bacteria  lead  either  a 
saprophytic  or  a  parasitic  existence.  A  "  saprophyte "  is 
one  that  grows  upon  dead  organic  matter — that  is,  it  devel- 
ops without  a  living  host ;  while  a  "  parasite  "  is  one  that  de- 
pends for  its  existence  upon  the  conditions  offered  by  either 
a  living  animal  or  plant,  in  or  on  which  it  develops.  There 
are  species  that  live  with — /.  e.,  that  are  commensal  with — 
both  animals  and  plants.     They  are  saprophytic  in  that  they 


6o  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

do  not  live  at  the  expense  of  their  host  and  have  no  deleteri- 
ous action  ;  in  fact,  they  are  frequently  of  importance  to  their 
host  by  aiding  in  the  performance  of  normal  physiological 
functions,  through  their  symbiotic  association. 

Both  saprophytes  and  parasites  have  their  obligate  and 
\\\€\\  facultative  varieties.  In  this  sense  the  term  "  obligate  " 
as  applied  to  a  saprophyte  implies  that  it  can  live  only  on 
dead  matter ;  when  applied  to  a  parasite,  that  it  can  develop 
only  within  a  living  host.  The  designation  "  facultative  "  as 
applied  to  a  parasite  or  a  saprophyte  implies  that  these  organ- 
isms possess  the  power  of  leading  either  a  parasitic  or  sapro- 
phytic form  of  existence,  according  to  circumstances. 

The  parasitic  bacteria  that  are  concerned  in  the  production 
of  those  diseases  in  which  all  the  postulates  of  Koch  have 
been  fulfilled  2S&  facultative  saprophytes,  as  it  is  possible  to 
cultivate  them  outside  a  living  host  on  dead  organic  nutritive 
media.  Had  they  been  obligate  parasites  this  would  have 
been  impossible,  and  it  may  be  due  to  their  obligate  nature 
that  certain,  presumably  present,  species  of  bacteria  elude  our 
efforts  to  cultivate  them. 

This  power  of  adaptability  to  surrounding  conditions  which 
is  common  to  the  facultative  saprophytes  ;  the  fact  that  after 
prolonged  existence  under  saprophytic  conditions  many  of 
them  experience  modifications  in  those  pathogenic  functions 
that  characterize  their  parasitic  life  ;  the  fact  that  by  a  variety 
of  artificial  procedures  modifications  of  other  important  bio- 
logical functions  may  be  induced,  have  served  as  a  basis  for 
occasional  discussion  relating  to  the  fixity  of  what  are  usu- 
ally considered  type-characteristics,  and  the  advisability  of 
con.sidering  the  different  specific  varieties  of  bacteria  as  definite 
and  distinct  species. 

As  generally  employed  by  biologists,  the  term  "  species  " 
implies  "  an  individual  which  differs,  or  collectively,  those 
individuals  which  differ  specifically  from  all  the  other  mem- 
bers of  the  genus,  and  which  do  not  differ  from  one  another 
in  size,  shape,  color,  and  so  on,  beyond  the  limits  of  individual 
variability,  as  tho.se  animals  and  plants  which  stand  in  the 
direct  relation  of  parent  and  offspring,  and  perpetuate  certain 


THE    CAUSATION   OF  DISEASE.  6 1 

inherent  characteristics  intact  or  with  that  little  modification 
which  is  due  to  conditions  of  environment." 

In  the  sense  of  this  definition  the  individual  peculiarities  of 
the  recognized  pathogenic  bacteria  are  of  sufficient  constancy 
to  justify  the  opinion  that  they  represent  functions  of  definite 
species. 

Nevertheless,  variations  both  of  form  and  function  are 
known  to  occur  under  the  influence  of  a  variety  of  condi- 
tions. Variations  in  function  are,  as  a  rule,  much  more 
lasting  and  more  frequently  encountered  than  are  variations 
in  form. 

The  majority  of  the  variations  that  one  observes  are  the 
result  of  injurious  conditions  concomitant  with  growth  under 
artificial  circumstances,  such,  for  example,  as  prolonged  sapro- 
phytic existence  of  facultative  saprophytes ;  growth  under 
unsuitable  conditions  of  nutrition ;  the  influence  of  dele- 
terious agents,  as  oxygen,  light,  heat,  and  hurtful  chem- 
icals ;  association  with  antagonistic  species ;  the  influence 
of  the  products  of  growth  of  other  bacteria ;  and  the  harm- 
ful influence  of  certain  animal  fluids  and  tissues. 

The  variations  in  form  most  commonly  seen  are  tempo- 
rary, are  the  result  of  unfavorable  conditions  of  life  and, 
as  a  rule,  disappear  under  the  influence  of  normal  environ- 
ment. The  commonest  of  such  morphological  changes  are 
those  indicative  of  degenerative  processes  in  the  bodies  of 
the  bacteria  themselves,  resulting  in  the  occurrence  of  the 
so-called  "  involution  forms." 

It  is  possible  by  prolonged  heating  and  by  the  application 
of  particular  chemicals  to  deprive  certain  bacteria  of  their 
power  to  form  spores.  By  special  methods  of  cultivation 
short  bacilli  have  been  induced  to  grow  as  longer  threads. 
The  color  characteristics  of  certain  chromogenic  species  have 
been  modified,  and  under  varying  conditions  of  nutrition  fluct- 
uations in  the  function  of  fermentation  are  observed.  By 
artificial  processes,  as  prolonged  heating  to  42°  C,  and  by 
the  action  of  certain  chemicals  in  a  dilute  form,  bacilhis 
anthracis  may  be  in  part  or  wholly  robbed  of  its  pathogenic 
properties.     On   the   other  hand,   exaltation   in   virulence  is 


62  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

often  seen  to  follow  the  repeated  passage  of  attenuated 
varieties  of  bacteria  through  susceptible  animals.  The  same 
result  sometimes  follows  the  mixing  of  attenuated  varieties 
with  other  species  of  bacteria  and  with  certain  chemical 
agents. 

As  a  general  rule,  the  structurally  modified  species  revert 
to  their  normal  morphology  when  placed  under  favorable 
conditions.  This  is  true  also  for  certain  functional  modifica- 
tions, though  those  that  appear  slowly  after  the  continued 
action  of  modifying  influences — such,  for  instance,  as  pro- 
longed heating — are  apt  to  be  lasting  and,  in  some  cases, 
hereditary. 

That  modifications  of  important  characteristics  appear 
naturally  there  can  be  no  doubt.  The  most  conspicuous 
example  of  this  is  the  loss  of  virulence  experienced  by 
many  pathogenic  species  when  expelled  from  the  diseased 
body  and  forced  to  compete  for  existence  with  the  host  of 
normally  saprophytic  forms  under  the  adverse  circumstances 
offered  by  the  soil,  water,  and  other  places  in  which  they  find 
themselves.  Striking  examples  of  this  are  seen  in  the  ba- 
cillus of  typhoid  fever,  the  colon  bacillus,  the  spirillum  of 
Asiatic  cholera,  the  streptococcus  of  eiysipelas,  viicrococciis 
lanceolatus  (pneumococcus)  and  the  group  of  organisms  con- 
cerned in  septic  infections. 

Notwithstanding  all  this  there  has  not  as  yet  been  pre- 
sented any  trustworthy  evidence  to  the  effect  that  by  any  of 
the  known  natural  phenomena  or  artificial  processes  one 
definite  bacterial  species,  as  recognized  by  the  available 
methods  of  study,  may  be  changed  into  another,  such,  for 
instance,  as  the  anthrax  into  the  subtilis  bacillus  or  the  colon 
bacillus  into  that  causing  typhoid  fever,  though  intermediate 
varieties  suggesting  probable  graduations  in  certain  peculiari- 
ties may  frequently  be  encountered. 


SECTION    II. 
THE  TRANSMISSIBLE  DISEASES. 

This  section  comprises  brief  sketches  of  the  commoner 
transmissible  diseases,  with  a  summary  of  points  that  are  of 
importance  to  the  hygienist,  such  as  the  causation,  modes  of 
dissemination,  portals  of  infection,  prophylaxis  against,  and 
the  geographical  distribution  of  such  diseases. 

In  this  summary  no  attempt  is  made  to  treat  of  the  various 
infectious  diseases  in  full.  The  object  is  to  emphasize  that 
knowledge  which  is  essential  to  a  rational  prophylaxis  against 
their  spread — such,  for  instance,  as  that  relating  to  the  agents 
concerned  in  "their  causation;  when  and  where  such  agents 
are  to  be  sought  for  ;  the  manner  in  which  they  are  expelled 
from  the  diseased  and  received  by  the  healthy  body ;  the 
steps  to  be  taken  to  prevent  the  dissemination  of  the  morbific 
factors ;  the  geographical  distribution  and  the  racial  suscepti- 
bilities to  and  immunity  from  such  diseases. 


TYPHOID  FEVER. 

Cause. — The  bulk  of  the  evidence  points  to  bacillus  typho- 
sus of  Eberth  and  Gaffky  as  the  specific  cause  of  this  disease. 

Bacillus  typhosus  is  a  short,  actively  motile,  flagellated, 
non-spore-forming,  non-Hquefying  rod  with  rounded  ends 
(Fig.  i).  It  does  not  possess  the  property  of  fermenting 
glucose  or  lactose,  nor  of  producing  indol  as  a  product  of  its 
growth  in  the  ordinaiy  nutrient  media.  It  does  not  coagu- 
late milk.  It  is  destroyed  in  ten  minutes  by  a  temperature 
of  60°  C.     It  is  not  destroyed  by  freezing.    When  inoculated 


64  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

into  animals  the  results  are  irregular.  Most  frequently  this 
has  no  effect.  Occasionally  evidences  of  intoxication  rather 
than  genuine  infection  are  obtained.  Exceptionally,  a  speci- 
men will  be  obtained  of  so  high  a  degree  of  virulence  that  it 
possesses  the  property  of  infecting.  By  none  of  the  ordinary 
methods  of  inoculation  are  conditions  produced  in  animals 


Fig.  I. — Bacillus  typhosus:  /,  stained  by  ordinary  methods;  //,  flagella  stained 
by  Loffler's  method. 

that  are  in  any  way,  either  clinically  or  pathologically,  com- 
parable to  those  found  in  the  human  being  suffering  from 
typhoid  fever.  By  a  few  investigators  lesions  of  the  intestine 
.similar  to  those  seen  in  the  human  being  are  claimed  to  have 
been  produced  by  special  methods  of  inoculation  in  particular 
.species  of  animals.  As  intimated,  these  results  are  by  no 
means  common. 

Mode  of  Dissemination. — Since  the  specific  micro- 
organism causing  the  disease  is  contained  in  the  discharges 
from  the  bowels  of  typhoid  patients,  and  is  apparently  at 
times  present  in  the  urine  also,  it  is  manifest  that  all  sub- 
stances with  which  these  matters  come  in  contact  may  be- 
come specifically  contaminated  and  be  capable  of  conveying 
the  disease. 

Typhoid  fever  is  disseminated  in  a  variety  of  ways,  but 
most  frequently  through  the  water,  the  soil,  and  through 


TYPHOID   FEVER. 


65 


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Charts  7  and  8  are  from  "The  Influence  of  Sewerage  and  Water-Supply 
on  the  Death-Rate  in  Cities,"  by  Erwin  F.  Smith,  Supplement  to  the  Annual 
Report  of  the  Michigan  State  Board  of  Health,  1885. 

5 


66  HYGIENE    OE   TRANSMISSIBLE   DISEASES. 

green  \'egetables,  salads,  etc.,  that  are  eaten  raw  and  that 
have  been  fertilized  with  human  manure.  It  is  not  infre- 
quentl}'  disseminated  by  milk  which  has  become  infected 
as  a  result  of  the  use  in  the  dairy  of  water  polluted  with 
typhoid  evacuations.  Attention  has  recently  been  directed 
to  raw  oysters  as  a  possible  disseminator  of  this  disease. 
The  outbreak  of  typhoid  fever  at  Wesleyan  College,  to 
which  Conn  directed  attention/  is  believed  by  him  to  have 
been  caused  by  the  use  of  oysters  that  had  been  "fattened" 
in  waters  polluted  with  typhoid  evacuations  ;  an  outbreak 
of  the  disease  in  England  is  believed  by  Broadbent^  to  be 
due  to  the  same  cause ;  and  numerous  experiments  point  to 
the  possibility  of  the  disease  being  conveyed  in  this  way.^ 
The  refuse  of  food  that  has  been  used  by  typhoid  patients 
should  be  looked  upon  with  suspicion,  and  should  under  no 
conditions  be  eaten  by  others  in  attendance. 

There  is  no  evidence  that  the  disease  is  disseminated 
through  the  air.  Milk  and  other  foods  may  be  infected  by 
insects  that  have  been  in  contact  with  fresh  typhoid  stools, 
and  thus  become  means  for  conveyance  of  the  infection. 

Portals  of  Infection. — The  disease  is  not  contagious. 
It  is  not  spread  by  breathing  the  same  atmosphere  with  a 
typhoid  patient. 

Infection  occurs  by  way  of  the  alimentary  tract — i.  c.  it 
results  from  actually  swallowing  materials  that  have  come 
directly  or  indirectly  from  the  bowels  of  individuals  affected 
with  the  disease.  We  have  no  evidence  that  it  occurs  in 
any  other  way. 

Prophylaxis. — It  is  now  generally  recognized  that  the 
most  potent  factors  in  diminishing  the  widespread  occurrence 
of  this  disease  in  communities  are  an  unpolluted  general 
water-supply  and  a  reliable  system  of  sewage  disposal  (see 
Charts  7  and  8).  The  conspicuous  decline  in  the  mortality 
from  typhoid  fever  that  has  followed  the  adoption  of  such 

'  Med.  Record,  Dec.  15,  1894.  ^  j^,.j[    j^j^^i^  Jour.,  Jan.  12,  1895. 

*  See  Supplement  to  Report  of  Medical  Officer  of  Local  Gov.  Board,  1894- 
95;  also  Brit.  Med.  Jour.,  1896,  report  by  G.  E.  Cartwright  Wood;  also 
Science,  Nov.  27,  1898. 


TYPHOID   FEVER. 


67 


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68  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

measures  in  man}'  of  the  larger  cities,  particularly  in  Europe 
and  Great  Britain,  and  in  a  few  in  this  country,  can  leave 
little  room  for  doubt  as  to  the  correctness  of  this  view  (see 
Chart  8). 

In  districts  where  the  water-supplies  are  obtained  from 
shallow  wells  there  is  probably  no  more  active  cause  of  the 
spread  of  this  disease  than  pollution  of  the  soil  by  cesspools 
and  privies.  In  such  localities  the  soil  is  often  saturated  with 
the  contents  of  privies  into  which  not  only  normal  intestinal 
contents  find  their  way,  but  also  the  evacuations  of  individ- 
uals suffering  from  this  malady.  It  is  therefore  plain  that 
the  most  important  domestic  prophylactic  measures  consist 
in  the  disinfection  of  the  bowel-discharges  from  all  suspicious 
cases  of  intestinal  trouble,  and  the  subsequent  disposal  of  such 
discharges  by  some  method  that  will  remove  them  quickly 
and  completely  from  the  neighborhood  of  human  habitations. 
This  latter  is  to  be  accomplished  in  cities  only  by  means  of 
an  efficient  sewage  system.  In  the  country,  where  sewers  do 
not  exist,  reliance  must  be  placed  in  the  disinfection  of  the 
stools  (see  chapter  on  Disinfection)  and  their  final  disposal 
upon  the  soil. 

The  domestic  prophylactic  measures  consist,  again,  in  care- 
ful disinfection  of  all  intestinal  contents  before  they  are  finally 
disposed  of  This  point  cannot  be  too  strenuously  urged ;  as 
the  stools  of  typhoid  patients  are  the  only  known  source  of 
the  disease,  and  as  they  are  easily  rendered  inert,  a  great  deal 
may  be  done  in  reducing  the  frequency  of  the  disease  by  faith- 
ful attention  to  this  point. 

All  body-  and  bed-clothing  of  the  patient  that  has  become 
soiled  by  intestinal  discharges  is  to  be  removed  at  once  and 
placed  directly  into  a  covered  vessel,  preferably  one  contain- 
ing a  cold  solution  of  carbolic  acid  in  water,  the  strength 
being  3  per  cent.  The  towels,  napkins  and,  in  fact,  all 
wash-goods  when  taken  from  the  patient  are  to  be  similarly 
treated.  They  should  remain  in  this  solution  for  about  two 
hours,  when  they  may  be  laundered  in  the  usual  way. 

If  it  is  desirable  to  subject  linen  or  muslin  articles  that  are 
stained  by  blood  or  fecal  matters  to  the  disinfecting  action  of 


TYPHOID   FEVER.  69 

either  steam  or  boiling  water,  the  stains  should  first  be  re- 
moved. This  is  easily  accomplished  by  soaking  them  for 
about  two  or  three  hours  in  a  cold  3  per  cent,  solution  of  car- 
bolic acid  and  finally  rinsing  them  thoroughly  in  a  fresh  por- 
tion of  the  same  solution.  This  removes  all  stains.  The 
articles  may  then  be  subjected  to  further  processes  of  disin- 
fection, if  desired,  by  either  boiling  or  steaming  in  a  steam 
disinfector.  Unless  the  stains  are  first  removed,  the  action 
of  moist  heat  renders  them  permanent,  and  they  cannot  be 
subsequently  removed  by  any  of  the  ordinary  processes  of 
laundering. 

The  eating  utensils,  of  which  the  patient  should  be  sup- 
plied with  a  set  for  his  exclusive  use,  are  to  be  scalded  thor- 
oughly with  boiling  water  after  each  meal.  The  refuse  of 
meals  is  to  be  at  once  scalded  or  burned. 

After  attending  the  patient  the  nurse  should  carefully  rinse 
her  hands  in  a  i  :  lOOO  solution  of  corrosive  sublimate,  after 
which  they  should  be  thoroughly  washed  in  warm  water  and 
soap,  and  scrubbed  with  a  nail-brush. 

All  valueless  articles  used  about  the  patient,  as  the  toilet 
paper,  or  rags  used  in  wiping  or  bathing  the  nates,  should  be 
burned  as  soon  as  used. 

In  times  of  epidemic  or  in  localities  in  which  the  disease  is 
more  than  usually  prevalent,  all  water  and  milk  should  be 
heated  to  from  60°  to  70°  C.  for  at  least  fifteen  minutes  before 
being  drunk.  It  should  be  cooled,  not  by  the  addition  of  ice, 
but  by  placing  it  in  the  ice-chest  in  a  vessel  that  has  been 
previously  scalded. 

In  localities  where  human  manure  is  used  as  a  fertilizer,  all 
green  vegetables  used  as  salads  should  be  regarded  with  sus- 
picion. Since  the  organism  causing  the  disease  is  easily  de- 
stroyed by  heat,  there  is  no  more  useful  aid  to  prophylaxis 
than  the  use  of  boiling  water. 

Geographical  Distribution,  Season,  Sex,  Age,  etc. 
— The  disease  occurs  in  all  countries,  perhaps  more  fre- 
quently in  temperate  than  in  countries  presenting  the  ex- 
tremes of  atmospheric  heat  and  cold.  It  is  a  disease  of  late 
summer  and  early  autumn,  the  greatest  number  of  casefe  usu- 


70  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

ally  occurring  between  the  latter  part  of  July  and  the  early 
part  of  October,  though  a  few  cases  may  be,  and  often  are, 
irregularly  scattered  throughout  the  year. 

Men  are  somewhat  more  frequently  affected  than  women. 
It  is  a  disease  of  youth  and  early  adult  life,  being  compara- 
tively infrequent  before  the  age  of  fifteen  and  after  forty-five 
years. 

Though  endemic  in  all  countries,  it  is  not  unusual  to  en- 
counter local  epidemics,  and  the  most  frequent  cause  of  such 
epidemics  is  the  domestic  use  of  polluted  water,  though  in- 
fected milk  has  on  various  occasions  been  shown  to  be  the 
disseminating  factor. 

It  may  serve  a  useful  purpose  to  present  the  details  of 
several  of  the  classic,  water-borne  outbreaks,  in  order  to 
illustrate  the  lines  along  which  evidence  pointing  to  their 
causation  has  been  accumulated. 

Epidemics  of  Typhoid  Fever. — The  Lausen  Epi= 
demic. — Conspicuous  among  them  may  be  mentioned  the 
oft-cited  outbreak  of  typhoid  fever  in  Lausen  in  Switzerland. 
This  village,  prior  to  the  outbreak  to  which  reference  is  made, 
had  never  been  visited  by  an  epidemic  of  typhoid  fever,  and 
for  years  there  had  not  been  known  a  single  sporadic  case  of 
the  disease.  In  1872  typhoid  fever  appeared  in  the  village, 
and  before  its  disappearance  about  17  per  cent,  of  the  inhabi- 
tants had  been  attacked. 

Lausen  is  situated  in  the  province  of  Basle  just  north  of 
the  mountain  ridge  Stockhalden  (Fig.  2),  which  separates  it 
from  the  Fiirlerthal.  In  a  solitary  farm-house  in  this  valley 
lived  a  peasant,  who  was  attacked  with  typhoid  fever  on  June 
10,  after  having  been  away  on  a  visit.  Between  June  10  and 
Augu.st  a  girl  and  the  farmer's  wife  and  son,  all  inmates  of 
the  same  house,  were  attacked  with  the  same  disease.  On 
Augu.st  7  the  disease  appeared  in  Lausen  and  almost  simul- 
taneously 10  individuals  were  stricken  down  ;  during  the 
ne.xt  ten  days  57  persons  were  affected  ;  by  the  end  of  the 
fourth  week  the  epidemic  numbered  100  cases,  and  at  its 
close  in  October  130  of  the  780  residents  of  the  town  had 
suffered  from  the  disease.      In  addition  to  this,  14  children, 


TYPHOID  FEVER. 


71 


Fig.  2. — Plan  of  Lausen  and  vicinity. 


72  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

who  had  been  spending  their  holidays  in  the  town,  developed 
the  disease  after  their  return  to  school. 

The  cases  were  pretty  evenly  distributed  throughout  the 
village,  with  the  exception  of  six  houses.  These  six  houses 
had  their  own  private  wells  from  which  their  domestic  water- 
supply  was  drawn.  This  fact  directed  suspicion  to  the  source 
from  which  the  town  drew  its  water-supply.  This  supply 
came  from  a  spring  at  the  foot  of  the  north  side  of  the  Stock- 
halden  ridge  which  separated  Lausen  from  the  farm-house  to 
which  reference  has  been  made.  Observations  upon  a  brook 
in  the  Fiirlerthal,  near  which  the  peasant  lived,  and  of  the 
water-supply  of  Lausen  gave  rise  to  the  suspicion — ulti- 
mately proved  to  be  correct — that  there  might  be  a  direct 
communication  between  the  two.  It  had  been  noted  that, 
ten  years  previously,  a  hole  had  spontaneously  formed 
in  the  soil,  a  little  below  the  farm-house,  and  that  whenever 
the  meadows  below  this  hole  were  inundated  by  water  from 
the  Furler  the  volume  of  the  spring  supplying  Lausen  be- 
came rapidly  augmented. 

The  Furler  was  in  direct  communication  with  the  closets 
and  dung-heaps  of  the  affected  house.  The  intestinal  evacu- 
ations from  the  inmates  were  thrown  into  it,  and  their  soiled 
clothing  was  washed  in  it,  and  it  was  with  the  waters  of  this 
brook  that  the  meadows  had  been  inundated  from  the  middle 
to  the  end  of  July.  The  epidemic  began  at  Lausen  about 
three  weeks  after  this  inundation.  To  fix  further  the  connec- 
tion between  the  polluted  water  of  the  Fiirler  and  the  spring 
at  Lausen,  Dr.  Hagler,  who  investigated  the  case,  made  an 
experiment  which  demonstrated  that  the  epidemic  in  Lausen 
was  the  outcome  of  the  use  of  water  polluted  by  the  dejecta 
from  the  patients  in  the  Fiirlerthal,  on  the  other  side  of  the 
mountain  ridge.  The  hole  near  the  farm-house  in  the  Fiir- 
lerthal was  opened,  and  the  brook  led  into  it ;  after  three 
hours  the  volume  of  water  given  out  by  the  spring  at 
Lausen  was  doubled ;  about  i8  hundred-weight  of  common 
salt  was  now  poured  into  the  hole,  and  in  a  very  short  time 
the  water  at  Lausen  gave  the  characteristic  chemical  reaction 
of  this  salt,  the  amount  of  which  gradually  increased  until 


TYPHOID  FEVER.    ■  73 

analysis  showed  the  amount  of  salt  present  to  be  about 
threefold  of  what  it  was  at  the  beginning. 

The  experiment  cleared  away  all  doubt  as  to  the  means  by 
which  the  disease  reached  Lausen,  and  the  channel  through 
which  it  was  disseminated. 

The  Wittemburg  Epidemic. — Still  another  example  of  the 
dissemination  of  typhoid  fever  through  drinking  water,  which 
is  of  interest  not  only  for  this  alone,  but  is  especially  instruct- 
ive as  an  illustration  that  this  disease  can  arise  only  from  the 
use  of  waters  that  are  contaminated  with  the  specific  causa- 
tive age?it  of  typhoid  fever,  and  that  the  use  of  water  not  so 
contaminated,  but  equally  foul  in  so  far  as  other  pollutions 
are  concerned,  does  not  result  in  the  appearance  of  this 
disease. 

The  case  in  point  is  recorded  by  Gaff  ky  ^  and  is  as  follows  : 

In  June,  1882,  there  appeared  among  the  privates  of  the 
3rd  Brandenburg  Infantry  regiment  located  at  Wittemburg, 
an  epidemic  of  typhoid  fever  which,  by  virtue  of  its  sudden 
appearance  and  dissemination  (Chart  9)  and  its  limitation  to 
one  battalion  of  this  regiment,  offered  a  favorable  prospect  for 
the  discovery  of  the  causes  underlying  its  existence. 

The  three  companies  of  this  battalion,  in  which  the  disease 
broke  out,  numbered  386  men,  226  of  whom  were  quartered 
in  the  arsenal,  while  the  remaining  160  were  quartered  in 
private  houses  in  the  town. 

Of  the  160  men  quartered  in  17  private  houses  in  the 
town,  24  suffered  from  typhoid  fever,  while  not  a  single  case 
occurred  among  the  other  inmates  of  these  houses.  Indeed, 
during  the  course  of  the  epidemic  not  a  single  case  was 
reported  among  the  citizens  of  the  town.  From  this  it 
seemed  probable  that  the  cases  of  typhoid  fever  that  had 
occurred  among  the  soldiers  quartered  both  in  the  barracks 
and  in  the  town  had  been  infected  from  the  same  source. 
After  careful  inspection  of  all  other  possible  channels  through 
which  the  men  could  have  become  infected,  the  water-supply 
was  finally  subjected  to  investigation. 

^  Gaffky  :  Mittheilungen  aus  dem  Kais.  Gesundheitsanite,  1884,  Bd.  ii., 
S.  410. 


74 


HVGIEXE    OF   TRANSMISSIBLE  DISEASES. 


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TYPHOID   FEVER.  75 

The  water  used  by  the  troops  was  supplied  by  two  wells, 
one  situated  in  the  yard  of  the  barracks  near  a  privy,  the 
other  just  outside  the  barracks  yard  in  the  neighboring 
Burgomeisterstrasse.  Upon  chemical  analysis  and  careful 
inspection,  both  wells  revealed  considerable  contamination, 
though  because  of  the  more  agreeable  taste  of  the  water  in 
the  well  outside  the  barracks  yard,  in  a  neighboring  street, 
this  was  more  commonly  used  for  drinking  purposes  by  both 
soldiers  and  citizens  than  was  the  water  of  the  well  within  the 
barracks  yard. 

Investigation  showed  that  some  time  prior  to  the  outbreak, 
typhoid  dejecta  had  been  thrown  into  the  barracks  privy, 
which  is  situated  about  50  feet  north  of  the  well  in  the  yard, 
and  upon  examining  the  walls  of  this  privy,  which  were 
cemented  and  had  hitherto  been  supposed  to  be  proof  against 
breakage,  two  cracks  of  appreciable  size  were  found,  through 
which  the  contents  had  leaked. 

The  strata  between  this  privy  and  the  well  were  for  the 
most  part  of  coarse  sand  and  gravel,  and  it  is  therefore 
probable  that  the  contents  of  the  privy  had  oozed  through 
the  loose  soil  into  the  well.  This  was  facilitated  probably  by 
three  factors  : 

(i)  The  lowness  of  the  water  in  the  well ;  (2)  the  increased 
amount  of  water  which  was  drawn  from  the  well  at  that 
season  of  the  year,  amounting  practically  to  an  aspiration 
upon  the  water  in  the  surrounding  soil ;  (3)  the  direction  of 
the  current  of  ground  water,  which  was  found  to  be  from  the 
privy  toward  the  well. 

In  Fig.  3  will  be  seen  the  relation  between  the  privy  and 
the  barracks  well,  while  in  Fig.  4  Avill  be  seen  the  relation 
between  the  barracks  and  the  houses  of  the  town,  particularly 
those  houses  in  which  soldiers  affected  with  typhoid  fever 
lodged,  and  those  houses  in  which  cases  of  the  disease  had 
existed  in  1881,  the  year  preceding.  From  the  general  con- 
ditions it  was  evident  that  suspicion  pointed  more  strongly  to 
the  water  of  the  well  in  the  yard  of  the  barracks  than  to  that 
of  the  well  in  the  neighboring  Burgomeisterstrasse,  for  the 
latter,  though  evidently  polluted,  was  less  likely  to  be  specif- 


76 


HYGIENE    OF   TRAXSMISSIBLE  DISEASES. 


Fig.  3. — -Plan  of  barracks  at  Wittemburg,  showing  the  relation  between  buildings 

and  well. 


TYPHOID   FEVER. 


77 


78  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

ically  polluted,  for,  as  stated,  there  were  no  cases  of  typhoid 
fever  among  the  citizens  using  water  from  this  well ;  and  as 
it  was  more  agreeable  in  taste  than  the  water  from  the  bar- 
racks well  it  was  customaiy  for  the  officers,  among  whom 
likewise  no  cases  of  typhoid  fever  occurred,  to  use  this  water, 
though  in  general  it  is  very  probable  that  the  officers  drank 
much  less  water  than  did  the  privates. 

The  water  from  the  well  in  the  yard  of  the  barracks, 
though  of  a  very  poor  character,  was  nevertheless  occasion- 
ally used  for  drinking  purposes  by  the  men. 

It  was  akvays  used  for  washing  dishes,  clothing,  and  par- 
ticularly for  rinsing  beer-mugs  and  canteens,  none  of  which 
are  ever  dried  after  washing,  but  only  allowed  to  drain. 

Though  subjected  to  a  most  careful  bacteriological  analysis 
by  Gaffky  himself,  no  typhoid  bacilli  were  detected,  a  result 
that  might  have  been  expected  a  priori,  for  by  the  time  the 
analyses  were  made  (at  about  the  end  of  the  epidemic)  the 
organisms  which  had  been  present  at  the  time  of  the  pollu- 
tion, through  which  the  battalion  became  infected,  had  dis- 
appeared. The  pollution  was  not  continuous,  and  in  all  prob- 
ability had  lasted  for  but  a  few  days,  when  it  did  occur. 

This  negative  evidence,  however,  by  no  means  weakens  the 
ground  taken  by  Gaffky  in  believing  this  well  to  have  been 
the  source  of  infection. 

The  Epidemic  at  Plymouth,  Pa.,  in  1885. — In  the  spring 
of  1885  the  mining  town  of  Plymouth,  Pa.,  of  about  8000  to 
9000  inhabitants,  was  visited  by  an  outbreak  of  typhoid  fever 
of  explosive  violence.  The  sudden  appearance  of  the  epi- 
demic, its  rapid  spread,  and  the  ultimate  demonstration  of  the 
underlying  cause,  make  it  one  of  the  most  instructive  of  the 
many  cases  of  this  kind  that  have  been  recorded.  From  60 
to  100  new  cases  occurred  daily,  and  on  one  particular  day 
200  fresh  cases  were  reported.  At  least  looo  of  the  9000 
inhabitants  were  stricken  down  with  the  disease. 

The  circumstances  surrounding  this  outbreak  were  of  such 
a  character  as  to  point  directly  to  the  drinking  water  as  the 
channel  of  infection. 

The  facts  tliat  were  elicited   upon  inspection  of  the  town 


TYP/IOW   FEVER. 


79 


Fig.  5. — Chart  of  Plymouth,  Pa.,  showing  sources  of  its  water,  and  the  dis- 
tribution of  the  polluted  supply  (line  in  red). 


TYPHOID  FEVER.  8 1 

and  its  surroundings  were  as  follows  :  Conspicuous  among 
the  data  recorded  was  the  fact  that  while  the  disease  was  gen- 
erally distributed  through  the  town,  it  occurred,  practically, 
only  in  those  houses  that  received  tJieir  water-supply  from  one 
special  source — /.  e.  the  general  water-supply  of  the  town  that 
is  obtained  from  a  series  of  reservoirs  situated  along  the 
course  of  a  rapidly-flowing  mountain  stream  that  skirts  the 
southwest  margin  of  the  borough.  From  these  reservoirs  it 
is  distributed  in  pipes  in  the  usual  way.  It  was  also  noticed 
that  in  those  houses  receiving  their  water  from  other  supplies 
or  those  having  private  wells,  either  no  cases  of  the  disease 
occurred  or  where  they  did  occur  it  was  only  among  the 
members  of  the  family  who  drank  of  the  general  supply 
while  away  from  their  homes,  during  the  business  hours  of 
the  day.  During  the  course  of  the  epidemic  it  was  not 
uncommon  for  the  disease  to  appear  in  almost  every  house 
on  one  side  of  a  street  supplied  with  water  from  the  reser- 
voirs, while  in  those  on  the  opposite  side  having  private  wells 
not  a  case  appeared. 

In  short,  the  disease  appeared  only  in  those  persons  who 
drank  of  the  hydrant  water  from  the  reservoirs  along  the 
course  of  the  stream  mentioned. 

Upon  further  investigation  it  was  discovered  that  between 
the  third  and  fourth  reservoirs  and  about  forty  feet  from  the 
banks  of  the  stream  (Fig.  5)  was  located  a  solitary  house  in 
which  there  had  been,  some  weeks  prior  to  the  outbreak,  a 
case  of  typhoid  fever.  The  facts  that  were  elicited  were 
these  :  One  of  the  occupants  of  this  house,  a  man,  had  visited 
Philadelphia  on  December  25,  1884,  and  while  there  had  con- 
tracted the  disease.  He  returned  to  his  home  in  Januaiy 
and  was  ill  with  typhoid  fever  for  many  weeks.  During  the 
course  of  his  illness,  according  to  the  statements  of  the 
nurses  and  attendants,  the  dejecta  that  were  passed  during 
the  night  were  thrown  upon  the  snow  within  a  few  feet  of  the 
stream  supplying  the  town  with  drinking  water,  while  the 
daily  evacuations  were  emptied  into  a  privy  the  contents  of 
which  lay  upon  the  surface  of  the  ground.  From  March  21 
to  March  23  the  temperature  of  the  atmosphere  became  suf- 


82  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

ficiently  elevated  to  melt  the  snow  that  up  to  this  time  had 
been  frozen  hard,  and  during  the  early  days  of  April  there 
were  frequent  warm  showers.  In  consequence  of  these 
atmospheric  conditions  the  entire  mass  of  dejecta  that  had 
been  passed  by  the  patient  during  the  course  of  his  illness 
was  washed  directly  into  the  stream  supplying  the  reservoirs 
from  which  the  town  obtained  the  largest  part  of  its  water. 

The  amount  of  pollution  was  therefore  exceptionally  great, 
and  the  disease-producing  elements  must  have  been  dissem- 
inated by  means  of  the  water  very  shortly  afterward ;  at  all 
events,  the  evidence  that  was  obtained  shows  that  the  first 
cases  of  the  epidemic  appeared  within  from  two  to  three 
weeks — the  period  of  incubation  of  typhoid  fever — after  the 
polluted  water  had  been  distributed  through  the  town. 

The  accompanying  is  a  chart  of  Plymouth,  with  sources 
of  its  water,  and  the  distribution  of  the  polluted  supply 
marked  — —  (page  79). 

The  Outbreak  in  Philadelphia  During  the  Winter  of 
1897-98. — The  city  of  Philadelphia  receives  its  water-supply 
in  large  part  direct  from  the  Schuylkill  river,  a  more  or  less 
grossly-polluted  stream  that  traverses  a  thickly-populated 
.section  of  Pennsylvania,  and  finally  unites  with  the  Delaware 
river  to  the  south  of  the  city. 

During  December,  1897,  January,  and  a  part  of  February, 
1898,  the  weekly  returns  of  the  Health  Officer  of  the  city 
revealed  the  fact  that  typhoid  fever  had  suddenly  appeared 
in  Philadelphia  to  such  an  extent  as  to  be  fairly  regarded  as 
epidemic  ;  the  number  of  cases  reported  between  November 
27,  1897,  and  March  i,  1898,  having  been  1927  as  compared 
with  628  cases  for  the  same  period  of  1896-97  and  as  against 
a  weekly  average  of  40  cases  for  the  eight  weeks  preceding 
December,  1897.  In  short,  during  the  period-  of  greatest 
prevalence  the  number  of  cases  reported  weekly  was  some- 
what over  three  times  as  great  as  under  usual  conditions. 

Upon  locating  these  cases  the  increase  was  found  to  be 
general  throughout  the  city,  but  the  niajorit)'  of  the  cases 
(about  65  per  cent.)  (occurred  within  a  siiarply-circumscribed 
area  in  the  northern   .section  of  thie  city  that  embraces  princi- 


TYPHOID   FEVER. 


Map  of  Philadelphia,  with  ward  boundaries. 


84  HYGIENE    OE   TRANSMISSIBLE   DISEASES. 

pally  the  15th,  20th,  28th,  29th,  32nd,  27th,  and  38th  wards 
(see  shaded  area  on  Map,  page  83),  having  a  population 
rouglil)-  representing  only  about  one-fifth  of  the  entire  popu- 
lation (census    1890). 

As  soon  as  this  state  of  affairs  became  evident  a  careful 
inspection,  including  chemical  and  bacteriological  analysis  of 
the  milk  and  water-supplies  of  this  section  especially,  was  or- 
dered by  the  Board  of  Health.  The  results  of  careful  studies 
upon  the  problem  by  laboratory  methods  shed  no  important 
light  upon  the  origin  and  mode  of  dissemination  of  the  disease. 

It  was  clear  to  those  engaged  upon  the  investigation  ^  that 
the  cause  of  the  outbreak  must  have  been  operative  at  some 
period  antecedent  to  the  epidemic  outbreak  of  the  disease ; 
that  infection  of  a  large  number  of  persons  must  have 
occurred  simultaneously  and  probably  through  the  same 
channel ;  and  that,  taking  four  to  six  days  as  the  time  neces- 
sary to  recognize  the  disease  and  notify  the  Board  of  Health, 
and  seven  to  ten  days  as  the  period  of  incubation  of  typhoid 
fever,  infection  must  have  occurred  during  the  week  ending 
November  20,   1897. 

On  referring  to  the  events  of  this  week  it  was  found  that 
on  the  afternoon  of  November  16  there  was  suddenly  de- 
posited into  the  Schuylkill  river,  as  a  result  of  the  overflow  of 
the  large  intercepting  sewer  that  carries  the  sewage  of  a  great 
portion  of  northern  Philadelphia,  a  large  volume  of  raw 
sewage.  The  point  at  which  this  occurred  was  located  on 
the  same  side  of  the  river  and  but  a  short  distance  up  stream 
(a  few  hundred  feet)  from  the  intake  of  the  pumping  station 
that  supplies  water  to  the  Queen  Lane  Reservoir.  At  the 
time  of  the  accident  and  for  about  two  hours  afterward,  the 
pumps  were  engaged  in  filling  this  reservoir,  and  a  very  large 
portion  of  the  grossly-polluted  water  must  have  been  pumped 
directly  into  it.  The  pumps  at  the  stations  located  further 
down  the  stream  were  stopped  a  few  hours  after  the  accident 
"  because  the  water  was  discovered  to  have  a  peculiarly  bad 

^  In  this  conneclion  I  wish  to  credit  Dr.  II.  \\.  Pease,  at  the  time  assistant 
in  the  Municipal  Laboratory,  with  all  that  is  due  him  for  valuable  services 
rendered. 


'rvrJlOID   FEVER. 


85 


Chart  10. — Sho-wing  incidence  of  typhoid  fever  in  Philadelphia. 
Black  bars,  for  the  entire  city ;  red  bars,  for  wards  in  Queeii  Lane 
district. 


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86  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

taste,"  so  that  all  the  reservoirs  below  the  point  of  pollution 
were  more  or  less  contaminated,  though  that  at  Queen  Lane, 
because  of  the  proximity  of  its  intake,  was,  as  subsequent 
events  demonstrated,  most  affected. 

Upon  inquiry  as  to  the  distribution  of  the  water  from  the 
Queen  Lane  Reservoir,  it  was  ascertained,  through  the  cour- 
tesy of  Mr.  J.  C.  Trautwine,  Jr.,  Chief  of  the  Bureau  of 
Water,  that  the  area  supplied  with  water  from  this  reservoir 
was  embraced  within  the  limits  of  the  wards  in  which  the 
largest  proportion  of  cases  of  typhoid  fever  occurred. 

The  connection,  therefore,  between  the  typhoid  cases  in 
these  wards  and  the  character  of  water  supplied  to  them 
was,  in  the  judgment  of  those  engaged  in  the  investigation, 
reasonably  established  ;  even  though  repeated  bacteriological 
examination  of  the  water  had  failed  to  demonstrate  the  pres- 
ence of  typhoid  bacilli  in  it. 

It  is  not  necessary  to  discuss  here  the  increase  of  typhoid 
fever  in  other  sections  of  the  city  ;  it  suffices  to  say  that  cir- 
cumstantial evidence  connects  it  also  with  the  polluted  water- 
supply.  By  reference  to  Chart  lo  the  progressive  incidence 
of  the  cases,  and  the  relation  between  those  in  the  most 
affected  district  and  those  in  the  city  generally,  will  be  seen 
graphically  represented.^ 

Chart  lo  shows  the  typhoid  morbidity  in  Philadelphia  in 
the  winter  of  1897-98.  The  period  represented  embraces 
two  months  prior  to  the  discharge  of  raw  sewage  into  the 
river,  and  three  months  after  the  epidemic  had  reached  its 
maximum.  (Compiled  from  official  reports  of  the  Health 
Officer.)  Black  bars  represent  the  number  of  cases  weekly 
for  the  entire  city.  Red  bars  represent  the  number  of  cases 
occurring  at  the  same  time  in  the  district  supplied  by  the 
Queen  Lane  Reservoir  into  which  the  greatest  amount  of 
sewage  was  pumped.  The  population  of  this  district  was 
about  one-fifth  of  the  entire  city. 

To  emphasize  further  the  important  relation  between  the 

*  For  details,  see  Annual  Report  of  Ihc  Department  of  Public  Safety  of 
Philadelphia,  1898;  section  referring  to  the  Division  of  Bacteriology,  etc., 
of  the   Hureau  of  IIe;iUh. 


TYPHOID   FEVER. 


87 


Chart  ii. — Showing  death-rates  fj-oni  typhoid  fevet'  iii  iSg^f.  in  66 
cities.     Grouped  according  to  the  quality  of  their  drinkitig  water. 


jo      10      20      30      40      50       60       70      80       90     100 

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JIYGJEXE    OF   TKAXSMISSIBLE   DISEASES. 


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ASIATIC   CHOLERA.  89 

health  of  communities,  particularly  as  regards  typhoid  fever, 
and  the  character  of  water  supplied  to  them,  the  accompany- 
ing chart  (Chart  11)  is  taken  from  the  instructive  studies  of 
Mr.  James  H.  Fuertes.  The  figures  at  the  right  hand  side 
represent  the  averages  of  the  annual  mortalities  in  each  group 
of  cities.     There  is  no  further  comment  needed. 

Chart  12  illustrates  the  influence  of  artificial  methods  of 
purification  of  a  polluted  water-supply  upon  the  health  of  the 
community  using  it.  For  the  twelve  years  prior  to  the  appli- 
cation of  filtration  to  the  water-supply  of  Hamburg,  Ger- 
many, the  average  annual  death-rate  from  typhoid  fever  was 
39.7  per  100,000  of  population ;  for  the  six  years  since 
filtration  was  established  the  average  death-rate  from  the 
disease  has  been  9  per  100,000;  and  for  the  year  1898  it 
was  5  per  100,000.  In  less  than  one  year  after  the  water- 
supply  of  Hamburg  was  filtered,  this  city  stepped  from  a 
place  in  the  lowest  to  one  in  the  second  group  of  Mr. 
Fuertes'  classification.^ 


ASIATIC  CHOLERA. 

Cause. — The  disease  results  from  the  invasion  of  the  body 
by  the  micro-organism  discovered  by  Koch  and  known  as 
spirilliuii  cliolercB  Asiaticce. 

The  spirillum,  or  "  comma  bacillus,"  of  Asiatic  cholera  is, 
as  its  name  implies,  a  curved  or  spiral  organism,  occurring 
most  frequently  as  short,  comma-shaped  rods.  It  is  motile, 
non-spore -forming,  liquefies  gelatin,  produces  indol,  and 
does  not  cause  fermentation  of  glucose  or  lactose.  At  times 
it  coagulates  milk,  while  again  it  does  not.  It  is  destroyed  by 
an  exposure  of  five  minutes  to  65°  C.  It  is  not  destroyed  by 
freezing.  According  to  different  authorities  it  is  destroyed  by 
drying  in  from  three  to  four  hours.     When  in  a  moist  condi- 

^  I  wish  to  express  my  obligation  to  Mr.  F.  Andreas  Meyer,  Chief  Engineer 
of  the  city  of  Hamburg,  for  his  courtesy  in  supplying  me  with  the  data  from 
which  Chart  12  was  compiled. 


90  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

tion  it  retains  its  vitality  often  for  months,  though  it  is  prob- 
able that  it  becomes  weakened  in  virulence  after  this  time. 

Its  morphological  and  cultural  peculiarities  are  not  suf- 
ficient to  lead  to  its  absolute  identification  by  these  means 
alone,  as  there  is  a  group  of  other  special  organisms  that  are 
in  many  of  these  respects  almost  identical  with  it.     During 


Fig.  6. — Spirillum  of  Asiatic  Cholera  :  /,  stained  by  ordinary  method  :  //,  stained 
to  show  flagella. 

the  prevalence  of  Asiatic  cholera — i.  e.  when  the  disease  is 
epidemic — the  finding  of  spiral  or  comma-shaped  organisms 
on  microscopical  examination  of  the  intestinal  discharges  of 
people  with  diarrhea  is  sufficient  to  justify  the  opinion  that 
the  case  is  suspicious  and  should  be  considered  as  cholera 
until  decided  to  be  otherwise. 

The  most  important  diagnostic  tests  for  this  organism  are 
its  failure  to  infect  pigeons  when  a  small  portion  of  a  solid 
culture  of  it  is  introduced  into  the  pectoral  muscle,  and  the 
test  with  the  serum  of  animals  immunized  against  cholera,  as 
devi-sed  by  Pfeiffer.  In  this  latter  procedure  genuine  cholera 
spirilla  when  brought  in  contact  with  the  serum  of  animals 
highly  immunized  (artificially)  from  Asiatic  cholera  lose  their 
motility,  and  gradually  accumulate  together  in  small  masses. 
(The  reaction  is  analogous  to  that  known  as  Widal's  reaction 
for  typhoid  fever.)     Spiral  organisms   that  are  not  etiologi- 


ASIATIC   CHOLERA.  9 1 

cally  related  to  cholera  when  subjected  to  this  test  experience 
no  change  in  their  normal  behavior/ 

After  neutralizing  the  acid  reaction  of  the  gastric  juice  and 
arresting  intestinal  peristalsis  with  opium,  Koch  succeeded  in 
producing  in  guinea-pigs  to  which  large  doses  of  cultures  of 
this  organism  were  given  per  os  a  condition  of  the  intestinal 
canal  that  was  pathologically  analogous  to  that  seen  in  cholera 
in  man. 

By  the  ordinary  methods  of  inoculation  no  effect  is  pro- 
duced, as  a  rule.  By  injection  into  the  peritoneal  cavity  of 
guinea-pigs  the  result  is  either  that  suggestive  of  depression 
due  to  acute  intoxication,  when  small  doses  are  employed,  or, 
when  large  doses  are  used,  these  symptoms  may  be  followed 
by  death  with  peritonitis  and  evidences  of  general  infection, 
though  the  latter  is  not  usually  conspicuous. 

Geographical  Distribution,  Season,  Race,  etc. — 
The  disease  is  endemic  in  India,  where  it  has  been  known  for 
centuries.  Epidemics  have  occurred  in  practically  all  coun- 
tries, in  each  instance  their  origin  being  readily  traceable 
either  directly  or  indirectly  to  the  delta  of  the  Ganges,  the 
home  of  the  disease.  Between  its  first  appearance  in  this 
country  in  1832  and  its  last  in  1873  there  have  been  eight 
outbreaks  of  varying  degrees  of  severity,  those  of  1832, 
1853-54,  and  1873  being  the  most  severe.  In  all  instances 
the  origins  of  these  epidemics  were  directly  traceable  to 
imported  cases  of  the  disease.  Since  1873,  though  the  dis- 
ease has  frequently  appeared  elsewhere,  there  have  been  no 
outbreaks  of  cholera  in  the  United  States. 

Epidemics  of  the  disease  are  much  more  apt  to  occur  in 
the  warm  than  the  cold  months,  and  have  been  known  to 
disappear  with  the  advent  of  cold  weather,  though  this  is  not 
always  the  case.  It  is  more  frequent  in  places  of  low  than  in 
those  of  high  altitude. 

According  to  Hirsch,  the  negro  is  more  susceptible  to  the 
disease  than  others  of  the  human  race,  while  the  Chinese  have 
often  shown  a  relative  insusceptibility  to  it. 

^  Pfeiffer :  Zeitschrift  filr  Hygiene  tind  Infektionskrankheiteii,  Bd.  xviii., 
S.  I  ;  ibid.,  Bd.  XX.,  S.  198. 


92  HYCIEXE    OF   TRANSMISSIBLE   DISEASES. 

Mode  of  Dissemination. — Cholera  is  one  of  the  non- 
co)itacrious,  infectious  diseases.  It  is  not  disseminated  through 
the  air.  The  specific  causative  element  is  contained  in  the 
e\-acuations  from  the  bowels  of  cholera  patients,  and  prob- 
ably only  in  the  evacuations,  though  it  is  sometimes  said  to 
be  present  in  the  vomited  matters. 

The  disease  is  disseminated  principally  through  the  water 
and  through  food  that  has  become  contaminated  with  the 
evacuations  of  cholera  patients. 

With  regard  to  the  epidemic  occurrence  of  cholera,  modern 
opinion  is  at  one  in  regarding  specifically  polluted  water  as 
one  of  the  most  important  factors  in  its  dissemination.  In 
the  voluminous  literature  on  the  subject  numerous  instances 
are  recorded  in  which  not  only  was  all  doubt  as  to  the  part 
played  by  water  in  spreading  the  disease  removed  by  circum- 
stantial evidence,  but  in  a  number  of  cases  the  actual,  specific, 
etiological  factor  in  the  malady  was  discovered  by  bacteriolog- 
ical methods.  No  more  striking  and  instructive  illustration  in 
this  connection  could  be  cited  than  the  cholera  epidemic  of 
Hamburg  and  Altona,  in  Germany,  in  the  autumn  and  winter 
of  1892  and  1893.  These  two  cities  merge  into  one  another 
without  any  definite  line  of  demarcation.  They  are  under 
distinct  forms  of  government.  Hamburg,  being  one  of  the 
old  free  cities,  retains  special  privileges,  while  Altona  is  under 
the  Prussian  government.  The  population  of  Hamburg  is 
about  640,400,  while  that  of  Altona  is  about  148,615.  Both 
cities  take  their  water-supply  from  the  river  Elbe.  At  the  time 
of  the  epidemic,  Hamburg  distributed  this  water  to  the  citizens 
just  as  it  was  pumped  from  the  river,  while  Altona  passed  it 
through  sand  filters  before  allowing  it  to  enter  the  city  mains. 
The  number  of  cases  of  cholera  in  Hamburg  during  the  epi- 
demic was  16,957  with  8606  deaths,  while  in  Altona  the  cases 
from  the  same  disease,  during  the  same  time,  numbered  only 
516  with  316  deaths:  in  other  words,  the  number  of  cases 
of  this  disease  in  the  city  receiving  Jtnfiltcrcd  water  was 
about  264.8  to  every  10,000  of  the  population,  while  in  the 
city  receiving  filtered  water  there  were  about  34.6  cases  to 
every  1 0,000  of  pf)pulation  ;  and  of  tliis  number,  it  must  be 


ASIA  riC  CHOLERA. 


93 


CHOLERA 


Fig.  7. — The  black  dots  show  the  location  and  number  of  the  cholera  cases  in 
both  Hamburg  (to  the  right  of  the  broken  dividing  line)  and  Altona  (to  the  left 
of  that  line). 


94  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

remembered,  many  drank  the  water  of  Hamburg  during  the 
time  of  their  occupation  in  that  city,  for  Hamburg  affords 
employment  for  many  residents  of  AUona.  Since  this  epi- 
demic of  1892  one  has  no  difficulty  in  determining  the 
boundary  line  between  Hamburg  and  Altona.  One  has  but 
to  represent  graphically  on  a  map  of  the  two  cities  the  loca- 
tions of  the  cholera  cases  (Fig.  7)  when  the  ramifications  of 
the  mains  carrying  Hamburg's  impure  water  stand  out  in 
marked  contrast  to  those  of  the  Altona  system  carrying 
filtered  water.  Since  this  epidemic  Hamburg  has  instituted 
a  most  elaborate  and  satisfactory  system  of  filtration,  and 
though  there  has  been  no  opportunity  to  test  this  system 
against  cholera,  its  efficiency  has  been  demonstrated  in 
another  way.  Prior  to  the  installation  of  this  method  of 
purifying  water  the  death-rate  from  typhoid  fever  in  Ham- 
burg was  high,  ranging  from  23  to  34  per  100,000  of  popu- 
lation ;  the  first  year  after  the  filters  were  put  in  operation  the 
typhoid  mortality  dropped  to  1 8  and  the  second  year  to  6  per 
100,000  of  population  (Fuertes). 

The  disease  may  be  transmitted  by  flies  and  other  insects 
that,  having  come  in  contact  with  the  stools  of  these  patients, 
convey  the  germs  of  the  disease  to  foods,  such  as  milk, 
cooked  meats,  fruits,  etc.  Experience  has  taught  that  it  is 
carried  from  places  in  which  it  is  endemic  or  epidemic,  along 
the  lines  of  travel  and  by  means  of  surface  water-courses. 

All  objects,  articles  of  body-  and  bed-clothing,  etc.,  that 
are  soiled  by  the  dejecta  of  cholera  patients  are  capable  of 
conveying  the  disease. 

The  general  concomitants  of  poverty,  such  as  overcrowd- 
ing, filth,  bad  food,  insufficient  clothing  and  shelter,  intem- 
perance, and  exhausting  labor,  especially  favor  its  dissemina- 
tion. 

Portals  of  Infection. — The  only  natural  mode  of  infec- 
tion with  which  we  are  acquainted  is  by  way  of  the  alimentary 
tract.  It  is  needless  at  this  place  to  enumerate  the  various 
ways  in  which  this  may  occur.  It  will  suffice  to  say  that,  as  in 
the  case  of  typhoid  fever,  one  must  actually  swallow  the  spe- 
cific micro-or^ranism  that  has  been  derived  from  the  bowels  of 


ASIATIC  CHOLERA.  95 

a  patient  sick  of  cholera.  It  is  appropriate  to  state  here  that 
in  experiments  on  animals  with  a  view  of  reproducing  the 
disease  through  the  administration  of  the  specific  organism 
by  the  mouth,  the  acidity  of  the  gastric  juice,  by  destroying 
the  organisms,  has  served  as  an  effectual  barrier  against  their 
growth  and  passage  into  the  intestines  in  a  living  condition. 
To  what  extent  similar  protection  is  afforded  to  healthy 
human  beings  it  is  impossible  to  indicate,  but  certainly,  in  the 
light  of  experiment,  we  may  look  upon  all  conditions  that 
tend  to  neutralize  or  diminish  the  acidity  of  the  gastric  juice 
as  predisposing  to  infection. 

Prophylaxis. — In  view  of  the  fact  that  in  practically 
every  instance  of  an  outbreak  of  this  disease,  in  countries  in 
which  it  is  not  endemic,  its  origin  has  been  traced  to  immi- 
grants from  localities  where  the  disease  is  present,  it  is  mani- 
fest that  a  careful  system  of  quarantine  should  be  established 
at  the  earliest  moment  after  conditions  become  threatening. 
Such  a-  system  should  embrace  not  only  a  suspension  of  the 
maritime  intercourse,  but  should  be  uninterruptedly  continued 
along  the  inland  borders  as  well. 

In  addition  to  this,  what  has  been  said  for  typhoid  fever, 
with  regard  to  the  cooking  of  all  foods  ;  disinfection  of  all 
excreta  ;  disinfection  by  steam,  hot  water,  or  chemical  means 
of  all  soiled  linen,  underclothing,  and  bed-clothing  ;  destruc- 
tion of  all  refuse  from  meals  ;  and  the  scalding  of  all  eating 
utensils  that  should  be  iiscd  exclusively  by  the  patient,  applies 
equally  to  Asiatic  cholera. 

In  times  when  the  disease  threatens,  neither  water  nor 
milk  should  be  used  that  has  not  been  previously  heated  to 
at  least  70°  C.  for  not  less  than  fifteen  minutes.  All  foods 
and  drinks  should  be  carefully  protected  from  the  access  of 
flies  and  other  insects,  since  some  of  these  may  have  been  in 
contact  with  the  evacuations  of  cholera  patients  and  thus 
serve  as  carriers  of  the  specific  agent  that  causes  the  disease. 

When  the  disease  prevails,  all  persons  suffering  from  diar- 
rhea, no  matter  how  insignificant  it  may  appear,  should  be 
regarded  as  suspicious  and  should  be  subjected  to  the  same 
vigilant  supervision  as  applies  to  genuine  cholera  patients  ; 


96  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

for  many  of  these  cases,  though  mild,  are  nevertheless  chol- 
era, and  are  capable  of  disseminating  cholera.  Because  of 
their  comparatively  innocent  nature  these  mild  cases  often 
escape  the  attention  that  their  importance  demands  ;  for  the 
same  reason  they  are  more  dangerous  than  the  outspoken 
cases  which  attract  attention  from  the  onset  owing  to  the 
severity  of  their  course.  Unless  it  be  borne  in  mind  that  the 
mild  cases,  some  of  them  not  even  confined  to  the  house,  are 
a  grave  menace  to  those  with  whom  they  are  associated, 
and  are  treated  as  such,  we  can  but  look  to  them  as  fruitful 
sources  for  the  dissemination  of  the  disease. 

Convalescents  from  cholera  should  be  kept  isolated,  and 
the  evacuations  from  the  bowels  should  be  thoroughly  disin- 
fected until  bacteriological  examination  demonstrates  that  the 
specific  micro-organism  causing  the  disease  has  disappeared 
from  the  evacuations.  These  individuals  should  be  permitted 
to  mingle  with  others  only  after  a  disinfecting  bath,  and  after 
having  been  supplied  with  clean  clothing  previously  disin- 
fected by  steam  or  boiling  water. 

Care  of  the  Dead. — After  death  a  firm  pledget  of  cotton, 
soaked  in  either  5  per  cent,  carbolic-acid  or  i  :  1000  corrosive- 
sublimate  solution  and  then  wrung  out,  should  be  placed  in 
the  anus  ;  the  body  should  be  wrapped  in  a  sheet  wrung  out 
in  either  of  these  solutions,  and  it  should  be  either  buried  or 
cremated. 

The  question  concerning  the  disposal  of  the  dead  is  one 
upon  which  some  discussion  has  arisen,  and  as  it  is  of  no  small 
importance,  it  might  be  of  interest  to  see  what  experiment 
has  taught  us  in  this  connection.  In  his  experiments  upon 
the  destiny  of  pathogenic  bacteria  in  the  dead  body,  von  Es- 
march  was  unable  to  detect  later  than  five  days  after  death 
living  cholera-spirilla  in  the  body  of  a  guinea-pig  that  had 
died  of  the  experimental  form  of  the  disease  ;  and  as  a  result 
of  experiments  performed  in  the  Imperial  Health  Bureau  at 
Berlin,  it  was  found  that  the  bodies  of  guinea-pigs  that  had 
died  of  cholera,  induced  by  Koch's  method  of  inoculation, 
contained  no  living  cholera-spirilla  when  exhumed  after  hav- 
ing been  buried  for  nineteen   days  in   wooden  boxes,  or  for 


AMCEBIC  DYSENTERY.  97 

twelve  days  in  zinc  boxes.  In  a  few  that  had  been  buried 
in  moist  earth,  without  having  been  encased  in  boxes,  the 
results  of  examinations  for  cholera-spirilla  were  likewise 
negative. 

There  does  not  seem,  therefore,  to  be  any  objection  to  the 
burial  of  the  bodies,  providing  the  interment  does  not  take 
place  in  a  locality  where  a  spring  or  water-course  could  be 
directly  contaminated ;  indeed,  on  the  contrary,  this  method 
of  disposing  of  infected  materials  generally  is  second  to 
cremation  only  in  its  requiring  a  longer  time  for  the  accom- 
plishment of  the  same  end. 


AMOEBIC  DYSENTERY, 

(  Tropical  Dysentery. ) 

Cause. — Because  of  its  constant  presence  in  the  anatomi- 
cal lesions  and  in  the  stools  of  persons  suffering  from  this 
disease ;  and  because  of  the  results  of  inoculation  experi- 
ments performed  by  Kartulis,  amoeba  dysenterice  (also  known 
as  amoeba  call)  is  now  generally  held  to  be  the  cause  of  the 
so-called  "  tropical  dysentery."  As  its  name,  "  amoeba,"  im- 
plies, it  is  a  unicellular,  contractile,  protoplasmic  organism 
(Fig.  8).  It  has  an  enveloping  ectosarc  of  clear  material  and 
an  endosarc  of  granular  protoplasm.  It  possesses  a  homo- 
geneous, refractive  nucleus,  and  usually  several  vacuoles  are 
to  be  seen  in  its  protoplasmic  body.  In  size  it  ranges  from 
0.012  to  0.035  mm.  in  diameter.  Kartulis  has  succeeded  in 
cultivating  it  in  hay  infusions  and  has  produced  dysentery  in 
cats  by  the  injection  of  these  cultures  into  the  rectum.^ 

It  may  be  remarked  that  in  examining  the  stools  of  dys- 
enteric patients  for  amoebae  there  are  certain  points  which,  if 
observed,  will  facilitate  their  detection.  The  amoebae  are  not 
uniformly  present  in  all  parts  of  the  stools.     They  are  most 

1  Kartulis:    Centralbl.  fur  Bakteriologie  tmd  Parasitenkunde,  1891,  Bd.  ix., 

s  365. 

7 


98  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

numerous  in  the  small,  grayish-yellow  pus  collections  that 
are  seen  to  float  in  the  brownish  fluid  of  the  stools.  They 
are  less  frequent  in  the  viscid,  blood-stained  mucus.  They 
are  rare  in  the  large  greenish  or  yellowish-brown  shreddy 
masses  of  detritus,  and  when  found  here  may  often  be 
motionless  (Lafleur). 

Amoebic  dysentery  is  therefore  to    be    considered    as    an 
infectious  disease,  the  morbific  causative  agent  of  which  is  of 


Fig.  8. — .Amoeba,  dysenteriae  (after  Councilman  and  Lafleur). 

the  family  of  protozoa.  It  is  not  contagious  in  the  sense  in 
which  contagion  is  ordinarily  understood. 

Geographical  Distribution. — It  occurs  both  endemic- 
ally  and  epidemically  everywhere  in  tropical  and  subtropical 
countries,  and  cases  have  been  encountered  in  practically 
all  European  countries  and  in  many  parts  of  the  United 
States. 

Mode  of  Dissemination. — The  amcebai  causing  the 
disease  are  passed  from  the  bowels  of  dysenteric  patients  in 
larger  or  smaller  numbers,  according  to  the  severity  of  the 
attack.  When  abscess  of  the  liver  is  secondary  to  the  intes- 
tinal lesions,  this  may  perforate  the  diaphragm,  open  into  the 
lung,  and  the  amoeba  may  then  be  found  in  the  expectora- 
tion. 

We  have  no  knowledge  of  the  life-histor)-  of  this  organism 


AMCEB/C  DYSENTERY.  99 

outside  the  body,  and  it  is  therefore  impossible  to  speak 
definitely  as  to  the  means  through  which  it  may  be  carried 
from  diseased  to  healthy  persons  ;  but  if  it  possesses  the  pecu- 
liarities common  to  other  amoebae  it  is  quite  probable  that  it 
finds  conditions  in  both  the  soil,  especially  marshy  soils,  and 
in  water  that  favor  its  existence  and  development.  It  is  not 
unlikely  then  that  water  and  soil,  when  polluted  with  the 
discharge  of  dysenteric  patients,  support  the  life  of  the 
organism  and  may  serve  as  potent  factors  in  spreading  the 
disease. 

There  are  grounds  for  the  suspicion  that  amoebae  capable 
of  causing  this  disease  are  more  or  less  constantly  present  in 
the  marsh  waters  of  many  tropical  places,  though  they  have 
not  been  detected  by  the  common  methods  for  isolating  such 
organisms. 

Portals  of  Infection. — The  commonest  recognized  por- 
tal of  infection  is  through  the  mouth — i.  e.  as  a  result  of  the 
use  of  water  or  uncooked  foods  in  or  on  which  the  organism 
is  located.  The  experiments  of  Kartulis  leave  no  doubt  that 
infection  can  occur  through  the  rectum,  though  this  is  prob- 
ably a  very  rare  mode  in  human  beings. 

Prophylaxis. — The  stools  of  dysenteric  patients  should 
be  carefully  disinfected  before  being  finally  disposed  of. 

When  the  disease  prevails,  uncooked  vegetables  should 
not  be  eaten,  and  only  water  that  has  been  boiled  should  be 
drunk. 

What  has  been  said  under  this  head  with  regard  to  typhoid 
fever  and  Asiatic  cholera  applies  with  equal  force  here. 


lOO  HYGIENE    OF    TRANSMISSIBLE   DISEASES. 


TUBERCULOSIS, 

Definition  and  Cause. — Tuberculosis  is  an  infectious 
disease  characterized  by  the  formation  of  nodular  bodies — 
tubercles — from  which  it  takes  its  name,  and  resulting  from 
the  presence  in  the  tissues  of  a  specific  micro-organism, 
bacillus  tuberculosis,  discovered  by  Koch  in  1881-82. 

Opinions  are  somewhat  at  variance  concerning  the  trans- 
missibility  of  tuberculosis,  particularly  the  pulmonary  form ; 
but  the  bulk  of  the  evidence  favors  the  opinion  that  the  dis- 
ease may  be,  and  often  has  been,  contracted  through  continu- 
ous respiration  of  the  air  of  apartments  occupied  by  tuber- 
culous individuals.  Not  that  the  consumptive  throws  off 
with  the  breath,  in  the  course  of  ordinary  respiration,  the 
specific  bacillus  of  the  disease,  for  this  is  not  the  case  ;  but 
rather  that  by  inattention  to  the  proper  prophylactic  meas- 
ures the  sputum  of  such  patients,  always  rich  in  living  tuber- 
cle bacilli,  is  expectorated  upon  the  floor,  into  napkins,  or  in 
other  undesirable  places,  becomes  dried,  ground  into  dust, 
and  in  this  form  is  inhaled  by  those  in  attendance  upon  the 
patient.  When  infection  or  transmission  occurs,  it  is  prob- 
ably to  be  explained  in  this  manner. 

The  bacillus  of  tuberculosis  is  a  slender,  rod-shaped  organ- 
ism usually  presenting  the  appearance  of  being  somewhat 
beaded.  It  is  believed  to  form  spores,  it  is  motionless,  it  cannot 
be  readily  cultivated  on  the  ordinary  nutrient  media,  though 
it  can  be  induced  to  lead  a  saprophytic  form  of  existence  on 
sterilized  blood-serum,  on  nutrient  agar-agar,  and  in  bouillon 
to  which  glycerin  has  been  added,  and  sometimes  on  potato. 
It  develops  under  these  conditions  only  at  the  temperature 
of  the  body.  It  is  destroyed  by  the  temperature  of  boiling 
water  in  a  few  minutes,  and  by  lower  temperatures  also,  but 
after  a  longer  time — viz.,  in  four  hours  by  55°  C,  in  fifteen 
minutes  by  65°  C,  in  five  minutes  by  80°  C.  It  is  not  de- 
stroyed by  either  diying  or  freezing.  In  the  dry  state  it  is 
much  more  resistant  to  heat  than  in  the  moist.  It  is  recog- 
nized  b)-   its   microchemica!    reaction    with    particular    dyes. 


TUBERCULOSIS.  lOI 

This  reaction  is  characterized  by  the  tenacity  with  which  the 
tubercle  bacillus  retains  the  staining,  even  when  subjected  to 
the  action  of  comparatively  strong  decolorizing  solutions. 
The  same  reaction  is  common  to  several  other  organisms — 
viz.,   the   bacillus   of   leprosy,   bacillus   of  syphilis,   and  the 


Fig.  9. — Stained  sputum  containing  bacillus  tuberculosis.     The  delicate  beaded 
rods  in  the  figure  are  bacillus  tuberculosis. 


smegma  bacillus.     (For  details  of  the  method  of  staining  and 
the  differential  tests  for  these  organisms,  the  reader  is  referred 
to  works  on  Bacteriology.) 
Geographical  Distribution,   Race,  Sex,  etc. — The 

disease  occurs  in  all  countries,  among  all  peoples,  and  at  all 
ages.  It  is  more  frequent  in  overcrowded  than  in  sparsely- 
settled  localities,  and  somewhat  more  common  in  low  than 
in  high  altitudes. 

The  American  Indians  and  the  negro  races  exhibit  a  marked 
susceptibility  to  the  disease,  as  do  also  the  offspring  from  the 
commingling  of  the  white  and  colored  races.  It  is  seen  in 
many  of  the  domestic  animals,  notably  bovines.  It  is  toler- 
ably common  in  pigs,  rare  in  sheep,  dogs,  and  cats.  Many 
of  the  wild  animals  in  which  tuberculosis  does  not  occur 
while  they  are  in  the  native  state  develop  the  disease  after 
confinement.  It  is  of  the  greatest  sanitary  importance  to 
note  the  fact  that,  amonsf  the  domestic  animals  in  which  the 


102  HYGIENE    OF    TRANSMISSIBLE   DISEASES. 

disease  occurs,  bovines,  especially  milch  cows,  are  most  often 
affected. 

Mode  of  Dissemination. — As  has  been  already  stated, 
the  part  played  by  heredity  in  disseminating  the  disease  is 
most  conspicuously  exhibited  in  the  perpetuation  of  a  par- 
ticular condition  of  vitality  that  renders  the  individual  en- 
dowed with  it  peculiarly  susceptible  to  this  form  of  infection. 

The  frequency  of  tuberculosis  in  the  young  of  tuberculous 
parents  cannot  always  be  referred  to  the  congenital  existence 
of  the  disease  ;  in  fact,  authorities  are  pretty  well  at  one  in 
the  opinion  that  this  is  rarely  the  case.  It  is  more  probably 
due  to  direct  infection  from  parent  to  child  through  their  very 
intimate  association.  It  cannot  be  denied,  however,  that 
intra-uterine  tuberculosis  of  the  fetus  is  occasionally  en- 
countered. 

Every  tuberculous  individual  is  a  source  from  which  the 
disease  may  be  further  disseminated.  This  is  conspicuously 
true  with  regard  to  those  afflicted  with  the  pulmonary  mani- 
festations. As  said  above,  the  sputum  of  consumptives  con- 
tains the  specific  causative  micro-organism — bacilhis  tuber- 
culosis— in  enormous  numbers.  When  such  sputum  is 
allowed  to  dry  and  become  ground  into  dust,  and  is  inhaled 
as  such  by  those  in  the  vicinity,  we  see,  most  probably, 
the  commonest  mode  of  dissemination  of  consumption. 
The  greater  frequency  of  the  pulmonary  over  other  forms  of 
the  disease  speaks  in  support  of  this  view. 

The  secretions  from  those  manifestations  of  the  disease 
usually  classed  as  "  surgical  tuberculosis  "  also  contain  the 
bacilli  or  their  spores,  and  are  capable  of  causing  tubercu- 
losis. With  tuberculosis  of  the  genito-urinary  tract  the 
bacilli  are  found  in  the  urine,  while  from  intestinal  tubercu- 
losis they  are  thrown  off  with  the  discliarges  from  the  bowels. 
From  skin-tuberculosis — lupus — they  escape  with  the  secre- 
tions and  with  the  i^articles  of  exfoliated  epidermis. 

An  important  factor  in  the  dissemination  of  tuberculosis  is 
its  occurrence  in  certain  domestic  animals,  especially  those 
used  as  ibod.  Though  there  is  still  a  controversy  with 
regard  to  the  danger  of  infection  from  the   use  of  flesh  and 


TUBERCCLOS/S.  IO3 

milk  of  tuberculous  animals,  it  should  be  borne  in  mind  that 
bacilhts  tuberculosis  has  been  found  in  both,  and  so  long  as 
this  is  the  case  these  substances  must  be  considered  as  pos- 
sible disseminating  factors,  if  not  rendered  harmless  by  thor- 
ough cooking. 

In  addition,  there  are  a  multitude  of  ways  in  which  dis- 
semination may  occur  when  consumptives  are  closely  and 
continuously  associated  with  healthy  individuals,  as  in  the 
case  of  man  and  wife,  of  parent  and  child,  of  patient  and 
nurse,  etc.  Without  detailing  every  possible  mode  of  dis- 
semination under  such  circumstances,  it  will  suffice  to  say 
that  the  most  frequent  are  perhaps  infection  through  the 
introduction  into  the  mouth  of  the  specific  causative  organ- 
ism, by  the  hands  that  have  been  soiled  with  sputum  or 
secretions  from  the  patient,  by  kissing  and  caressing,  by 
using  the  same  eating  utensils  and  drinking  from  the  vessels 
used  by  the  patient,  and  by  sleeping  in  the  same  bed  with 
the  diseased  person. 

Portals  of  Infection. — The  commonest  portals  of  infec- 
tion in  man  are  the  lungs,  the  alimentaiy  tract,  and  wounds 
of  the  skin.  The  disease  may  be  produced  experimentally 
in  susceptible  animals  by  subcutaneous  inoculation,, by  inter- 
peritoneal  inoculation,  by  direct  injection  into  the  vascular 
circulation,  by  the  feeding  of  tuberculous  materials,  by  the 
introduction  of  the  bacilli  into  the  air-passages,  and  by  inocu- 
lation into  the  anterior  chamber  of  the  eye. 

Contrary  to  the  general  rule  for  pathogenic  bacteria,  ba- 
cillus tuberculosis  apparently  has  the  property  of  forming 
spores,  or  of  passing  into  a  resistant  condition  analogous  to 
that  of  the  spore-stage,  within  the  living  body.  When  thrown 
off  from  the  diseased  body  these  resistant  forms  of  the  bacil- 
lus survive  the  unfavorable  conditions  that  they  encounter, 
such  as  drying,  low  temperature,  scarcity  or  lack  of  nutritive 
material,  etc.,  and  retain  the  power  of  producing  tuberculosis, 
when  conditions  favorable  to  the  exhibition  of  this  function 
again  present.  The  investigations  of  Cornet  demonstrate 
that  bacillus  tJibcrculosis  in  full  possession  of  its  pathogenic 
powers   may  often   be    found    in   the   dust   of  rooms   occu- 


I04  nVG/EXE    OF    TRANSMISSIBLE   DISEASES. 

pied  by  tuberculous  individuals.  Some  of  the  details  of 
these  in\^estigations  are  most  instructive :  In  1 47  samples  of 
dust  collected  from  general  hospital  wards,  from  asylums, 
from  prisons,  from  private  apartments  of  consumptives,  from 
surgical  wards  of  hospit?ls,  and  from  other  localities  occa- 
sionally visited  by  consumptives,  bacillus  tuberculosis  was 
demonstrated  (by  inoculation  into  guinea-pigs)  to  be  present 
59  times — viz. : 

In  38  dust  samples  from  seven  hospitals  it  was  found  20  times 

"II          "                  "     three  asylums  "  "  3  " 

"5          "                  "     two  prisons  "  "  o  " 
"62          "                  "     private  apartments 

of  consumptives  "  "  34  " 

"3          "                   "     surgical  wards  "  "  O  " 

"  28         "                  "     other  localities  "  "  2  " 


From  this  it  is  clear  that  the  inhalation  of  dust  contaminated 
with  this  organism,  by  individuals  naturally  susceptible  or 
vitally  predisposed  to  this  variety  of  infection,  must  be  a 
comparatively  frequent  channel  through  which  the  disease  is 
contracted. 

It  is  not  my  intention  to  open  here  the  familiar  controversy 
as  to  whether  flesh  and  milk  of  bovines  affected  with  the 
lymphatic  or  pulmonary  form  of  the  disease  contain  the 
bacillus  of  tuberculosis  or  not,  but  rather  to  call  attention  to 
the  point  that  through  the  careless  handling  of  such  flesh 
and  milk  by  butchers  who  slaughter  tuberculous  cattle,  and 
by  dairymen  who  obtain  the  milk  from  diseased  cattle,  both 
meat  and  milk  may  become  accidentally  infected,  and  if  used 
in  the  uncooked  .state  may  serve  as  sources  of  infection. 

Tuberculosis  as  a  result  of  direct  inoculation — i.e.  through 
wounds  of  the  skin — is  less  important  to  man  than  are  the 
preceding  modes  of  infection.  When  it  does  occur,  the 
process  is  usually  localized  to  the  site  of  infection.  Tliere 
is  reason  to  believe,  however,  that  general  tuberculosis 
may  follow  this  mode  of  infection,  though  such  a  result  is 
rare. 

The  localized  tubercular  nodule  resultinir  from  infection  of 


TUBER  Ci  L  OS  IS.  I O  5 

wounds  of  the  skin,  familiarly  known  as  "  post-mortem " 
tubercle,  is  encountered  most  frequently  in  those  whose 
duties  bring  them  in  intimate  contact  with  the  morbid  tissues 
of  deceased  tuberculous  individuals  and  animals,  as  pathol- 
ogists, butchers,  workers  in  raw  hides,  etc. 

Prophylaxis. — The  most  important  prophylactic  meas- 
ure is  thorough  disinfection  of  the  sputum  and  other  dis- 
charges from  persons  suffering  from  the  various  manifesta- 
tions of  the  disease.  Cornet  states  that  for  the  ten  years 
ending  with  1897  the  death-rate  from  consumption  in  Ger- 
many was  21.5  per  10,000  against  3 1.4  for  a  corresponding 
previous  period.  He  believes  the  result  due  to  more  general 
efforts  at  the  suppression  of  indiscriminate  spitting  and  more 
care  in  preventing  tuberculous  sputum  from  becoming  dried 
and  disseminated  through  the  air  as  dust. 

The  patient  should  be  impressed  with  the  fact  that  he  is  a 
possible  source  of  infection,  and  that  it  is  quite  within  his 
power  to  control  the  spread  of  the  disease  from  himself  by 
attention  to  a  few  simple  details  that  will  in  no  way  interfere 
with  his  comfort. 

If  he  be  suffering  from  pulmonary  consumption,  the 
sputum  should  be  spat  into  covered  vessels  containing  a  dis- 
infectant fluid,  or  into  a  vessel  containing  plain  water,  which 
is  subsequently  to  be  boiled.  Cheap  paper  sputum-cups 
that  can  be  burned  after  use  are  now  to  be  had  of  all  drug- 
gists. The  cups  to  receive  the  sputum,  other  than  those  of 
paper  that  are  to  be  burned,  should  be  of  china  or  enamelled 
ware,  and  should  be  thoroughly  scalded  with  boiling  water 
at  least  twice  daily.  When  the  patient  is  away  from  his 
apartments  and  cannot  use  the  sputum-cup,  he  should  be 
provided  with  cheap  handkerchiefs  or  napkins,  into  which 
he  should  expectorate,  which  should  be  burned  after  using. 
A  very  good  form  of  handkerchief  for  this  purpose  is  the 
paper  "  Japanese  handkerchief" 

Bed-clothing  or  night-clothing  soiled  with  tuberculous 
sputum  should  be  at  once  removed  and  scalded.  The  con- 
sumptive should  be  provided  with  his  own  eating  utensils, 
napkins,  etc.,  and  these  should  be   used  by  him  alone,  and 


106  HYGIEXE    OF   TRANSMISSIBLE   DISEASES. 

should  be  scalded  immediately  after  use.  The  refuse  from 
his  meals  should  also  be  scalded ;    never  used  by  others. 

The  living-  and  the  bed-room  of  the  patient  should  be  kept 
scrupulously  clean,  and  should  be  frequently  aired.  Under 
no  circumstances  should  spitting  about  the  room  be  per- 
mitted. "  Dusting "  should  not  be  practised,  but  when 
necessary  all  objects  should  be  wiped  with  a  cloth  moistened 
in  I  :  looo  corrosive-sublimate  or  3  per  cent,  carbolic-acid 
solution.  The  importance  of  this  precaution  is  conspicuously 
illustrated  in  Cornet's  investigations,  cited  above,  by  the 
marked  difference  between  the  dusts  from  medical  wards  of 
hospitals,  where  there  is  more  or  less  of  laxity  concerning 
the  importance  of  cleanliness  as  a  factor  in  asepsis,  and 
the  dusts  from  surgical  wards,  where  this  point  is  kept  con- 
stantly in  mind.  Kissing,  caressing,  shaking  hands,  and 
other  modes  of  intimate  association  should  not  be  indulged  in 
by  the  consumptive.  The  hands  should  be  thoroughly  washed 
after  manipulating  tuberculous  patients. 

By  thorough  cooking  tuberculous  meat  and  milk  are  ren- 
dered free  from  danger.  The  slaughter  of  animals  for  public 
consumption  should  be  under  authorized  inspection  and  con- 
trol, and  the  entire  carcasses  of  animals  found  to  be  tubercu- 
lous should  be  discarded  and  burned  or  buried.  Similarly, 
dairy  herds  should  be  periodically  inspected  by  qualified 
veterinarians,  and  the  sale,  of  milk  from  all  suspicious  ani- 
mals should  be  prohibited.  Tuberculous  individuals  should 
not  be  engaged  about  dairies.  In  recommending  that  the 
marriage  of  consumptives  should  be  discouraged,  the  writer 
appreciates  the  almost  total  impracticability  of  the  sugges- 
tion ;  but  it  is  nevertheless  the  duty  of  the  physician  to  dis- 
courage such  unions  whenever  the  opportunity  presents  for 
him  to  do  so. 


ACUTE    CROUPOUS   PNEUMONIA.  IO7 

ACUTE  CROUPOUS  PNEUMONIA. 

^Lohar  Pneumonia.) 

Definition,  Cause,  etc. — An  acute,  specific  inflammation 
of  the  lungs  due,  in  the  vast  majority  of  cases,  to  the  pres- 
ence in  the  diseased  area  of  viicrococciis  lanccolatiis  (pneu- 
mococcus).  In  a  very  small  proportion  of  instances  pneu- 
monia, with  all  its  anatomical  and  clinical  characteristics* 
has  been  observed  to  follow  the  invasion  of  other  species 
of  bacteria — viz.,  streptococcus  pyogenes,  pneumobacillus  of 
Friedlander,  and  streptococci  and  stapJiylococci  pyogenes  to- 
gether. In  this  disease  the  part  played  by  a  predisposing 
cause  appears  to  be  eminently  essential  to  infection.  While 
manifestly  infectious,  there  is  some  room  to  doubt  that  the 
disease  is  contagious  in  the  strict  sense  of  the  word,  though 
numerous  local  outbreaks  (house-epidemics,  prison-epidemics, 
barrack-epidemics,  etc.)  have  been  recorded. 

Micrococcus  Imiceolatus,  also  known  as  diplococcns  pneii- 
inoni(B,  pneumococcus  of  Frankel,  streptococcus  lanceolatus 
Pasteuri,  Micrococcus  pncianonicB  crouposcB,  diplococcus  lan- 
ceolatus capsulatus,  micrococcus  of  sputum-septicemia,  and 
meningococcus,  is,  as  its  name  implies,  a  lancet-shaped  mi- 
crococcus, usually  found  in  pairs,  though  occasionally  in 
short  chains.  When  in  pairs  the  broad  ends  of  the  lancet- 
shaped  cells  are  in  juxtaposition.  When  examined  directly 
from  the  diseased  lung,  as  in  the  rusty  sputum  of  patients,  it 
is  found,  by  appropriate  methods  of  staining,  to  be  enveloped 
by  a  delicate  capsule  (Fig.  10),  though  under  artificial  cultiva- 
tion the  capsule  is  rarely  observed. 

Micrococcus  lanceolatus  is  not  conspicuous  for  its  sapro- 
phytic tendencies  ;  it  is  difficult  to  cultivate,  and  at  times 
loses  its  vitality,  after  three  or  four  generations,  under  arti- 
ficial circumstances.  Under  these  conditions  it  often  becomes 
rapidly  diminished  in  virulence,  though  this  is  not  always  the 
case.  It  is  constantly  present  in  the  mouth-cavity  of  from  15 
to  20  per  cent,  of  healthy  individuals  ;  by  some  it  is  thought 
to  be  present  in  the  mouth  of  every  one  at  one  time  or  an- 
other, and  it  is  found  in  the  sputum  of  practically  all  persons 


108  JIYGIEXE    OF   TKAXSMISSIBLE   DISEASES. 

suffering  from  croupous  pneumonia.  It  is  demonstrated  to 
be  the  cause  of  a  number  of  other  pathological  conditions — 
viz.,  meningitis,  acute  ulcerative  endocarditis,  pericarditis, 
otitis  media,  acute  circumscribed  abscess,  and  pleuritis.  It 
is  an  organism  of  very  low  resisting  powers,  and  is  readily 


Fig.  io. — Micrococcus  lanceolatus  (pneumococcus)  in  blood. 

destroyed  by  either  thermal  or  chemical  methods  of  disin- 
fection. 

It  does  not  grow  at  a  temperature  lower  than  25°  C,  nor 
above  42°  C.  The  temperature  most  favorable  to  its  growth 
is  that  of  the  body — viz.,  about  37°  C.  Its  thermal  death- 
point  is   52°  C.  in  ten  minutes  (Sternberg). 

It  is  very  pathogenic  for  white  mice  and  rabbits,  less  so  for 
guinea-pigs.  Subcutaneous  inoculation  of  these  animals  with 
this  organism  does  not  result  in  the  production  of  pneumonia, 
but  instead,  the  animals  succumb  to  a  rapidly-fatal  form  of 
septicemia.  Pneumonia  may,  however,  be  produced  in  a  fair 
proportion  of  cases  by  the  injection  of  either  cultures  of  this 
organism,  or  the  juices  from  a  pneumonic  lung  directly  into 
the  lung-substance  through  the  wall  of  the  thora.x. 

Geographical  Distribution,  Age,  Sex,  etc. — Pneu- 
monia does  not  appear  to  be  more  frequent  in  one  country 
than  in  another.  It  occurs  in  both  hot  and  cold  climates. 
It  is  most  frecjuent  in  tliis  latitude  during  January,  Februaiy, 


ACUTE    CROUPOUS  PNEUMONIA.  109 

and  March.  It  attacks  all  ages — men  more  frequently  than 
women,  and  the  aged  more  often  than  the  young. 

Modes  of  Dissemination. — Though,  as  stated,  micro- 
coccus lanccolatus  usually  loses  its  pathogenic  properties 
in  a  short  time  after  having  been  cultivated  under  arti- 
ficial circumstances,  it  is  nevertheless  observed  to  retain  its 
virulence  for  a  comparatively  long  time  in  sputum,  blood, 
and  other  pathological  exudates.  Even  when  dried  under 
these  conditions,  it  has  been  found  to  be  virulent  for  as  long- 
as  fifty-five  days.  It  is  not  unlikely,  therefore,  that  dried 
pneumonic  sputum  may,  when  ground  into  dust,  serve  as  a 
means  for  the  dissemination  of  pneumonia,  just  as  dried 
tubercular  sputum  is  believed  to  be  an  important  factor  in 
spreading  tuberculosis. 

When  a  number  of  cases  occur  simultaneously  or  in  rapid 
succession  in  isolated  localities,  the  outbreak  beginning  with 
almost  explosive  violence,  as  is  sometimes  the  case,  it  is 
reasonable  to  assume  a  common  depressing  influence  that 
predisposes  numbers  of  persons  to  infection  from  some 
common  source ;  these  individuals  then  in  turn  serve  as 
sources  for  the  further  spread  of  the  disease.  As  the  pneu- 
monic patient  is  the  source  from  which  the  most  highly 
pathogenic  varieties  of  the  causative  organisms  are  obtained, 
it  is  clear  that  an  individual  predisposed  by  one  debilitating 
influence  or  another,  when  intimately  associated  with  the 
patient,  would  present  conditions  eminently  favorable  to 
direct  infection.  The  fact  that  the  disease  is  not  commonly 
regarded  as  transmissible  explains  the  indifference  on  the 
part  of  many  to  precautions  against  infection,  and  it  is 
probably  through  such  laxity  that  the  disease  is  at  times 
contracted. 

Furthermore,  predisposing  influences  may  so  reduce  the 
normal  resistance  of  the  individual  as  to  favor  auto-infection 
from  his  own  mouth  or  nose-cavity  by  micrococcus  lancc- 
olatus that  had  hitherto  existed  there  as  a  harmless  com- 
mensal species.  Pneumonia  is  especially  apt  to  follow  upon 
exposure  to  sudden  and  extreme  variations  in  temperature, 
upon  exposure  to  excess  of  cold   and   moisture,  and  upon 


no  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

the  debilitating  effects  of  exhaustion,  alcohoHsm,  traumatism, 
and  diseases  of  other  kinds. 

Portals  of  Infection. — Our  knowledge  of  the  subject 
does  not  permit  of  a  definite  statement  as  to  the  relative 
frequency  of  infection  from  extraneous  sources  and  auto- 
infection  from  the  mouth,  or  from  other  primaiy  foci  of  dis- 
ease in  the  body.  Nevertheless,  there  is  eveiy  reason  to 
believe  that,  whatever  the  source  of  infection  may  be,  the 
disease  results,  in  the  vast  majority  of  cases,  from  the 
deposition  of  the  morbific  agent  in  the  tissues  of  the  lungs, 
from  either  the  mouth  or  nasal  cavities,  directly  or  by  way  of 
the  lymphatic  or  vascular  circulation. 

While  much  less  frequent,  it  is  still  probable  that  pneu- 
monia sometimes  arises  as  a  phenomenon  secondary  to  a 
primary  site  of  pneumococcus  infection  in  the  body,  the 
causative  agents  being  carried  from  the  diseased  area  to  the 
lungs  by  the  circulating  fluids  or  wandering  cells. 

Prophylaxis. — The  most  important  prophylactic  meas- 
ures are  those  directed  to  the  maintenance  of  the  general 
tone  of  the  body — /'.  e.  those  that  tend  to  support  the  normal 
vital  resistance  of  the  tissues ;  for,  as  stated  above,  this  par- 
ticular variety  of  infection  is  conspicuously  favored  by  all 
those  predisposing  causes  of  disease  that  tend  to  depress  the 
general  vitality. 

Careful  attention  should  be  paid  to  the  hygiene  of  the 
person,  including  regular  meals  of  nutritious  food,  protection 
by  proper  clothing  from  the  influence  of  sudden  and  extreme 
changes  of  temperature  and  of  excessive  cold  and  moisture, 
rational  e.xercise  in  the  fresh  air,  and  frequent  bathing.  The 
excessive  use  of  alcohol  is  generally  regarded  as  a  conspic- 
uous factor  in  predisposing  to  pneumonia. 

Those  who  are  in  attendance  on  pneumonia  patients  should 
remember  that  the  .sputum  of  such  patients  contains  the  living 
morbific  agents,  and  that  it  retains  its  power  of  infecting  even 
after  being  dried.  The  sputum  should  therefore  be  received 
in  covered  cups  containing  fluid ;  these  should  be  scalded 
with  boiling  water  three  or  four  times  daily.  Should  the 
hands   become  soiled  with  the   s^jutum  they  should  at  once 


DIPHTHERIA.  I  1 1 

be  washed  with  soap  and  water,  and  should  always  be  thor- 
oughly washed  before  meals.  Attendants  should  refrain  from 
unnecessary,  intimate  contact  with  the  patient.  Eating-uten- 
sils, refuse  of  food,  soiled  clothing,  etc.,  should  be  scalded  as 
soon  as  removed  from  the  ward  or  sick-room. 

The  sick-room  should  be  kept  thoroughly  clean,  should 
be  well  aired  without  draughts,  and  should  be  properly  lighted. 

Attendants,  often  exhausted  by  their  prolonged  duties 
with  the  patient,  should  observe  carefully  the  directions 
given  above,  and  should  bear  in  mind  that  they  especially, 
owing  to  the  frequency  of  their  lowered  physical  condition 
and  to  their  constant  association  with  the  patient,  offer  con- 
ditions most  favorable  to  infection.  They  should  be  particu- 
larly attentive  to  their  personal  hygiene,  and  should  endeavor 
to  spend  a  part  of  each  day  in  the  open  air. 


DIPHTHERIA. 


Cause. — Diphtheria  results  from  the  pathogenic  activity 
of  bacillus  diphtlierice ,  discovered  microscopically  by  Klebs, 
and  subsequently  isolated  in  pure  culture  and  proved  by 
Loffler  to  stand  in  causal  relation  to  the  disease.  This 
organism  is  therefore  also  known  as  the  Klebs-Loffler  bacillus 
of  diphtheria. 

Diphtheria  is  an  infectious  disease  which  is  also  generally 
regarded  as  contagious. 

Bacillus  diphtheri(Z  is  a  non-motile,  non-liquefying,  non- 
spore -bearing  rod  that  is  conspicuous  for  the  irregularity  of 
its  morphology.  It  may  be  recognized  in  microscopical 
preparations,  from  either  diseased  area  or  from  cultures,  by 
the  following  peculiarities :  It  occurs  as  irregularly  stained 
rods  with  one  or  both  ends  swollen ;  as  rods  broken  at 
intervals  into  short,  sharply-defined  segments  of  either  a 
round  or  an  oval  shape  ;    as  longer  rods  markedly  clubbed 


112  HYGIEXE    OF   TR.U\SMISSIBLR   DISEASES. 

at  one  or  both  ends,  and  as  short  oval  or  lozenge-shaped 
bt)dies.  In  some  preparations  one  or  another  of  these  forms 
will  predominate  ;  in  others  they  may  all  be  observed  together. 
As  a  rule,  they  stain  irregularly.  Occasionally  they  take  on 
the  dye  with  a  moderate  degree  of  regularity.  Often  sharply 
defined,  ver)'  deeply  .stained  round  or  oval  points  will  be  seen 
in  the  individual  cells.  It  stains  with  the  ordinary  basic 
anilin  dyes.  It  grows  readily  on  most  of  the  ordinary 
nutrient  culture-media,  especially  those  of  a  feebly  alkaline 
reaction  that  can  be  kept  at  the  body-temperature.     It  is  not 


Fk;.  ii.-^Showing  three  morphological  variations  of  bacillus  diphtherise :  /, 
as  seen  on  glycerin  agar-agar ;  //,  as  ordinarily  seen  on  neutral  or  slightly 
alkaline  Loffler's  blood-serum  mixture  ;  ///,  as  seen  on  slightly  acid  blood-serum 
mixture. 

readily  destroyed  by  drying,  and  under  these  circumstances 
has  been  known  to  retain  its  vitality  for  from  ten  to  fourteen 
weeks.  It  is  readily  destroyed  by  both  thermal  and  chemical 
means.  Its  thermal  death-point  is  58°  C.  in  ten  minutes.  It 
is  destroyed  in  cultures  by  the  direct  action  of  sunlight  in 
from  thirty  to  forty-five  minutes.  It  is  highly  pathogenic  for 
guinea-pigs  and  kittens  ;  much  less  so  for  other  animals  used 
for  experiment.  By  subcutaneous  inoculation  in  guinea-pigs 
there  is  produced  a  local  condition  that  is  in  many  ways 
analogous  histologically  to  that  seen  locally  in  the  throat  of 
human  beings.     1^)\'  introduction  into  the  trachea  of  kittens  a 


DIPHTHERIA.  I  1 3 

pseudomembranous  exudate  may  be  produced  that  is  in  all 
respects  similar  to  that  occurring  in  man. 

In  human  diphtheria,  and  in  the  experimental  form,  the 
specific  micro-organism  is  usually  found  only  at  the  local  site 
of  disease.  By  special  methods  they  may  often  be  detected 
at  more  remote  parts  of  the  body,  but  in  only  very  small 
numbers.  When  present  in  the  internal  organs  they  do  not, 
apparently,  play  any  part  in  the  general  process.  The  dis- 
ease does  not  result,  therefore,  from  the  general  invasion  of 
the  body  by  the  causative  micro-organism,  but  from  the  dis- 
semination of  soluble  poisons  elaborated  by  it  at  the  local 
site  of  disease  to  which  its  activities  are  confined.  It  is  to 
the  action  of  these  poisons  that  the  constitutional  symptoms, 
the  secondary  or  concomitant  manifestations,  and  the  remote 
degenerative  processes  of  organs,  commonly  seen  in  diph- 
theria, are  due. 

Geographical  Distribution,  Season,  Age,  etc. — The 
disease  has  been  known  since  the  time  of  Galen.  It  has 
been  observed  in  practically  all  countries.  It  received  its 
name  and  was  first  definitely  described  and  identified  as  a 
distinct  affection  by  Bretonneau,  of  Tours,  in  1826,  though 
in  1 77 1  a  pamphlet,  entitled  An  Inquiry  into  the  Nature, 
Cause,  and  Cure  of  the  Angina  Siiffocation,  etc.,  was  pub- 
lished by  Samuel  Bard,  of  New  York,  in  which  was  given  a 
description  of  the  cHnical  and  anatomical  manifestations  of 
diphtheria  that  was  quite  comparable  in  its  wealth  of  essential 
details  to  that  subsequently  given  by  Bretonneau. 

The  disease  is  more  common  in  cold  and  temperate  than 
in  hot  climates.  It  prevails  much  more  extensively  during 
the  autumn  and  early  winter  than  at  other  seasons.  It  is 
endemic  in  cities ;  it  frequently  appears  in  an  unusually 
severe  epidemic  form  in  country  districts.  It  occurs  at  all 
ages,  but  the  greatest  number  of  cases  fall  between  the  third 
and  fifteenth  years  of  life. 

Modes  of  Dissemination. — Though  contagious,  it  is 
nevertheless  probable  that  the  disease  is  rarely  contracted  by 
simply  breathing  the  air  of  rooms  occupied  by  diphtheritic 
patients,  for  the  reason  that  the  specific  micro-organism  is 

8 


114  I/YGlEiVE    OF  TRANSMISSIBLE  DISEASES. 

not  contained  in  the  breath  of  the  patient,  and  is  not  elimi- 
nated in  this  way  in  the  course  of  ordinary  quiet  respiration. 
It  is,  however,  dislodged  during  coughing,  sneezing,  gagging, 
etc.,  along  with  minute  particles  of  false  membrane  from  the 
fauces.  Nurses  and  physicians  are  especially  liable  to  have 
bits  of  membrane  coughed  into  their  faces  during  the  usual 
manipulations  about  the  throat  of  the  patient.  It  is  accidents 
of  this  kind  that  make  the  duties  of  attendants  on  diphtheria 
patients  particularly  dangerous,  and  it  is  among  such  attend- 
ants that  instances  of  direct  infection  occurring  in  this  way 
are  frequently  observed.  It  is  also  to  be  noted  that  the 
bacillus  of  diphtheria  is  not  readily  destroyed  by  drying,  and 
that  when  dislodged  from  the  throat  in  bits  of  false  mem- 
brane it  may  retain  its  vitality  for  a  long  time.  When  such 
particles  of  dried  membrane  are  disintegrated,  dissemination 
may  occur  through  the  breathing  of  air  laden  with  this  infec- 
tive dust.  Similarly,  napkins,  clothes,  towels,  handkerchiefs, 
bed-  and  night-clothing,  on  which  saliva  from  the  patient  has 
been  allowed  to  dry,  may  serve  in  this  way  to  spread  infec- 
tion. Wright  and  Emerson  detected  living  diphtheria  bacilli 
in  the  hair  and  on  the  shoes  of  nurses,  and  in  a  broom  in  the 
diphtheria  ward  of  the  Boston  City  Hospital. 

Through  inattention  to  the  hands,  soiled  while  manipulat- 
ing the  patient,  the  disease  may  readily  be  disseminated.  In 
short,  all  modes  of  immediate  contact  with  the  diseased  per- 
son offer  opportunities  for  infection.  There  is  a  pretty  wide- 
spread belief  that  domestic  animals  are  instrumental  in  spread- 
ing the  disease.  This  opinion  is  based  on  the  fact  that  cer- 
tain animals,  notably  calves,  cats,  and  chickens,  suffer  from  a 
pseudomembranous  inflammation  of  the  mucous  membrane 
of  the  upper  air-passages  that  has  been  taken  to  be  diph- 
theria. This  view  is  usually  erroneous.  Those  affections 
common  to  animals,  that  simulate  diphtheria  in  man,  are  eti- 
ologically  totally  distinct  from  human  diphtheria,  and  genu- 
ine diphtlieria  cannot  be  contracted  from  animals  affected 
with  those  diseases.  It  must  be  said,  however,  that  cats  are 
reported  to  have  suffered  from  diphtheria  contracted  from 
human  beings. 


DIPHTHERIA.  1 1  5 

A  number  of  epidemic  outbreaks  of  the  disease  have  been 
traced  to  the  milk-supply  of  those  affected.  This  has  given 
rise  to  the  supposition  that  one  or  more  of  the  cattle  from 
which  the  milk  was  obtained  were  diphtheritic.  There  is  no 
trustworthy  evidence  that  cattle  ever  suffer  spontaneously 
from  a  disease  capable  of  transmitting  diphtheria  to  man. 
When  "  milk-epidemics "  of  diphtheria  do  occur,  they  are 
probably  in  all  cases  due  to  contamination  of  the  milk  with 
the  genuine  diphtheritic  virus  from  human  sources — /.  e. 
from  the  family  of  the  dairyman,  or  from  some  of  the  others 
through  whose  hands  it  passes  before  reaching  the  con- 
sumers. 

There  is  no  evidence  to  support  the  opinion  that  the  dis- 
ease is  disseminated  by  the  water.  Neither  is  there  any  evi- 
dence, though  opinion  in  abundance,  that  the  disease  is  spread 
by  the  air  of  drains  and  sewers.  Where,  through  defective 
plumbing,  there  is  a  direct  passage  for  the  infective  materials 
thrown  into  closets  and  sinks,  through  leaks  in  the  soil-pipes, 
it  is  manifest  that  the  disease  may  be  spread  by  such  mate- 
rials finding  their  way  into  other  parts  of  the  building  and  not 
into  the  sewers,  as  intended.  Barring  such  a  condition  as 
this,  it  is  difficult  to  conceive  the  way  in  which  the  air  from 
sewers  may  play  a  part  in  disseminating  diphtheria,  or  in 
fact  any  other  variety  of  infection.  All  statistics  show  us 
that  those  constantly  engaged  about  sewers,  and  on  sewage 
farms,  are  not  more  liable  to  infective  diseases  than  are  those 
following  other  occupations.  The  air  of  sewers  is  poorer  in 
micro-organisms  of  all  kinds  than  is  that  of  the  overlying 
streets ;  the  chemical  composition  of  the  air  of  sewers  is  not 
such  as  to  warrant  the  opinion  that  it  is  irritating  and  when 
breathed  predisposes  the  respiratory  mucous  membranes  to 
infection  by  its  irritating  qualities ;  moreover,  when  leaking 
into  a  room  it  becomes  so  diluted  by  the  air  in  the  room  as 
hardly,  if  appreciably,  to  alter  the  chemical  composition  of 
that  air. 

Portals  of  Infection. — For  faucial  diphtheria  the  por- 
tals of  infection  are  the  nose  or  mouth.  Diphtheritic  inflam- 
mations, etiologically  identical  with  diphtheria,  are  occasion- 


Il6  HYGIENE    OE   TRANSMISSIBLE   DISEASES. 

ally  observed  in  other  localities — viz.,  on  other  exposed 
mucous  surfaces,  as  conjunctiva,  vagina,  etc.,  and  upon 
wounds  of  the  skin  that  have  become  infected  with  the  spe- 
cific diphtheria  virus.  During  the  course  of  the  disease  in 
the  fauces,  auto-infection  of  wounds  on  exposed  surfaces  of 
the  body  is  not  rare. 

Infection  of  the  nasal  mucous  membrane  often  results  in  a 
more  or  less  chronic  process,  known  as  membranous  or 
fibrinous  rhinitis,  though  the  acute  manifestation  of  the  dis- 
ease is  likewise  observed  in  this  locality. 

Prophylaxis. — The  most  modern,  and  certainly  the  most 
important,  prophylactic  measure  is  that  through  which  a  con- 
dition of  immunity  from  the  disease  is  afforded  by  the  sub- 
cutaneous injection  of  the  blood-serum  from  an  animal  that 
has  been  artificially  rendered  highly  immune  from  the  poison 
of  diphtheria.  As  the  immunity  thus  induced  is  not  perma- 
nent, lasting  for  but  a  few  weeks  at  most,  this  procedure  is 
only  employed  when  healthy  persons  are  directly  exposed  to 
the  disease,  especially  as  in  the  case  of  the  well  children  of  a 
family  in  which  the  disease  is  present. 

As  the  site  of  infection  is  the  local  area  of  diphtheritic 
inflammation,  it  is  plain  that  all  objects  in  any  way  contam- 
inated with  matters  from  this  area  are  infective,  and  should  be 
scalded  as  soon  as  removed  from  the  patient.  These  patients 
should  be  provided  with  separate  eating  utensils,  which  should 
be  scalded  after  each  meal.  The  refuse  from  meals  should 
be  scalded  with  boiling  water.  Soiled  bed-  and  body-clothing 
should  be  scalded  before  the  secretions  are  permitted  to  dry 
upon  them ;  or,  where  this  is  not  practicable,  the  soiled  areas 
should  be  moistened  with  3  per  cent,  carbolic-acid  or  i  :  lOOO 
corrosive-sublimate  solution. 

Nurses  and  physicians  should  guard  against  infection  by 
thoroughly  washing  and  disinfecting  the  hands  immediately 
after  manipulating  the  patient.  While  spraying  or  otherwise 
attending  to  or  examining  the  throat,  a  cotton  mask,  moistened 
with  either  of  the  above-named  solutions,  should  be  worn  ; 
this  to  guard  again.st  infection  that  might  otherwise  result 


DIPHTHERIA.  I  I  / 

from  bits  of  membrane  being  coughed  into  the  mouth,  nose, 
or  face. 

These  patients,  where  possible,  should  occupy  a  room  in 
an  unfrequented  part  of  the  house,  and  should  be  isolated,  in 
the  full  sense  of  the  word,  as  completely  as  possible ;  that  is 
to  say,  only  those  in  immediate  attendance  should  have  access 
to  the  room,  and  all  articles  that  have  been  about  the  patient 
should  be  scalded  or  otherwise  disinfected  before  they  leave 
the  sick-chamber. 

From  the  standpoint  of  prophylaxis  it  is  important  to  note 
that  the  diphtheria  bacilli  do  not,  as  a  rule,  disappear  from  the 
throat  with  the  disappearance  of  the  false  membrane,  but 
often  persist  far  into  the  period  of  convalescence.  In  the 
experience  of  the  Laboratory  of  the  Board  of  Health  of  Phil- 
adelphia it  is  found  that  the  average  period  of  persistency  of 
diphtheria  bacilli  in  the  throats  of  convalescents  from  this  dis- 
ease is  twenty-nine  days,  reckoned  from  the  date  of  establish- 
ment of  the  diagnosis  by  the  primary  bacteriological  exami- 
nation. In  one  case  they  were  present  after  one  hundred  and 
twelve  days,  while  in  a  very  few  cases  they  disappeared  as 
early  as  the  seventh  day  after  their  first  detection. 

Because  of  the  persistence  of  the  infective  agent  in  the 
throat  of  these  patients,  convalescents  from  diphtheria  are 
now  regarded  as  dangerous  sources  of  infection  until  they 
are  shown  to  be  otherwise  by  bacteriological  examination  of 
the  throat — /.  e.  until  such  examinations  demonstrate  the 
disappearance  of  the  bacilli. 

Note. — Processes  of  disinfection  are  given  in  the  Section  devoted  to  that 
subject. 


Il8  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

EPIDEMIC   CEREBROSPINAL   MENINGITIS   (CERE- 
BROSPINAL FEVER;  SPOTTED  FEVER )» 

Definition,  Cause,  etc. — An  acute  infectious  disease, 
the  clinical  manifestations  of  which  are  referable  to  a  sero- 
purulent  inflammation  of  the  meninges  of  the  brain  and 
spinal  cord. 

Though  sporadic  cases  are  occasionally  encountered,  the 
tendency  of  the  disease  is  to  appear  simultaneously  among  a 
number  of  the  individuals  of  a  community. 

The  cause  of  the  disease  is  now  generally  regarded  as  the 
micrococcus  described  by  Weichselbaum  in  1887  under  the 
name  of  diplococciis  intracelhdaris  meningitidis.  As  its 
name  implies,  this  organism  is  found  usually  in  pairs,  the 
surfaces  in  juxtaposition  being  flattened,  and  usually  located 
within  the  bodies  of  the  pus-cells  of  the  exudate  in  veiy  much 
the  same  way  that  the  gonococcus  is  located  in  the  pus-cells 
of  gonorrhea  (see  Fig.  16).  It  can  readily  be  detected  in  the 
cerebrospinal  exudates  in  genuine  cases  of  this  disease  by 
microscopical  examinations  of  cover-slip  preparations.  Its 
detection  in  this  way  in  the  spinal  exudate  obtained  by  lum- 
bar puncture  during  the  early  stages  of  the  disease  places  the 
diagnosis  beyond  doubt. 

This  organism  can  be  cultivated,  but  with  difficulty.  The 
media  most  favorable  to  its  cultivation  are  the  solidified  blood- 
serum  mixture  of  Loffler  and  nutrient  agar-agar,  though 
occasionally  it  will  not  develop  on  either,  even  though  it 
may  have  been  easily  detected  in  the  exudate  on  microscopi- 
cal examination.  It  grows  only  at  body-temperature.  It  is 
decolorized  when  treated  by  the  method  of  Gram.  It  stains 
with  the  ordinaiy  anilin  dyes.  Councilman,  Mallory,  and 
Wright  found  that  cultures  of  it  lost  their  vitality  in  eight 
da)'s  ;  that  ^\•hen  dried  it  died  in  from  twenty-four  to  seventy- 
two  hours,  according  to  circumstances  ;  that  it  was  killed  in 
from  four  to  seven  hours  by  exposure  to  mixtures  of  formal- 
dchyd  gas  and  air  in  proportions  of  from  i  :  7500  to  i  : 
225,000;  and  that  a  solution  of  i  :  800  carbolic  acid  prevents 
growth. 


EPIDEMIC  CEREBROSPINAL   MENINGITIS.  II9 

The  results  of  the  injection  of  either  the  exudate  or  of  cult- 
ures from  it  into  animals  in  the  ordinary  ways  are  uncertain. 
Heubner,  and  Councilman,  Mallory,  and  Wright  succeeded 
in  producing  the  typical  pathological  lesions  of  the  disease  by 
direct  injections  into  the  subarachnoidal  space  of  the  goat. 
Heubner's  animal  died  in  thirty-six  hours,  while  that  of  the 
Boston  investigators  lived  for  only  seventeen  or  eighteen 
hours ;  both  of  which  experiences  testify  to  the  very  great 
virulence  of  the  materials  employed  by  them. 

It  must  be  borne  in  mind  that  epidemic  cerebrospinal  men- 
ingitis should  not  be  confused  with  the  other  forms  of  menin- 
gitis from  which  it  is  etiologically  distinct.  Sporadic  cases  of 
cerebrospinal  meningitis  are  from  time  to  time  encountered, 
the  etiological  factors  of  which  are  not  the  same  in  all  in- 
stances. Typical  cerebrospinal  meningitis  may  be  caused 
by  streptococcus  pyogenes,  by  micrococcits  lanceolatiis  (pneu- 
mococcus),  and  by  bacillus  tuberculosis,  though  tubercular 
meningitis  has  certain  anatomical  points  of  distinction  that 
readily  aid  in  its  identification.  These  types  of  meningeal 
infection,  unlike  epideviic  cerebrospinal  meningitis,  show  no 
tendency  to  occur  in  the  form  of  widespread  outbreaks,  but, 
as  stated,  are  encountered  only  as  sporadic  cases. 

History,  Distribution,  etc. — The  first  authentic  ac- 
count of  this  disease  as  it  is  to-day  recognized  is  that 
given  by  Vieusseaux  of  the  epidemic  in  Geneva  in  1805  ; 
though  there  can  be  no  doubt  that  the  disease  had  appeared 
elsewhere  prior  to  that  date.  Since  then  epidemics  of  vary- 
ing degree  have  been  described  in  almost  every  part  of  the 
civilized  world.  The  year  after  the  description  of  the  disease 
by  Vieusseaux,  Danielson  and  Mann  first  called  attention  to 
its  occurrence  in  this  country.  After  its  primary  appearance 
in  Massachusetts  in  1806  it  continued  throughout  New  Eng- 
land in  various  localities  for  the  subsequent  ten  years.  In  his 
elaborate  article  Hirsch  distributes  the  epidemic  occurrence 
of  this  disease  through  four  periods,  namely  1805- 1830; 
1837-1850;  1854-1875;  1876  to  date.  In  the  first  period 
it  appeared  in  isolated  epidemics  in  Europe  and  to  a  much 
greater  extent  in  the  United  States  ;  in  the  second  period 


I20  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

widespread  epidemics  occurred  in  France,  Italy,  Algeria, 
the  United  States,  and  Denmark ;  during  the  third  period  it 
included  Europe,  Asia,  Africa,  South  America,  and  the 
United  States  ;  while  in  the  last  period  it  has  been  especially- 
marked  in  German)',  Italy,  and  the  United  States.  In  com- 
menting further  upon  this  disease  Hirsch  expresses  the  opin- 
ion that  it  is  becoming  more  and  more  circumscribed  in  its 
occurrence  and  that  it  can  hardly  be  longer  regarded  as  an 
endemic  disease  of  the  people. 

A  singular  feature  of  the  disease  is  its  comparativ^e  lack  of 
extension  by  continuity.  Its  appearance  in  a  community  is 
usually  characterized  more  by  its  simultaneous  occurrence 
in  a  number  of  individuals,  not  necessarily  closely  associated, 
than  b)-  its  gradual  extension  from  one  person  to  another.  It 
is  also  common  for  the  disease  to  manifest  itself  in  widely 
scattered  localities;  thus,  for  instance,  in  1857  it  appeared 
simultaneously  in  North  Carolina  and  in  western  New  York. 
It  is  manifest  that  the  peculiar  distribution  and  occurrence  of 
the  epidemics  in  no  wise  tend  to  simplify  the  study  of  all  the 
factors  concerned  in  their  causation,  dissemination,  etc. 

Its  outbreak  at  some  time  and  place  may  comprise  but  a 
few  scattered  cases,  while  at  another  place,  but  simulta- 
neously, large  numbers  may  be  affected.  At  one  period  it 
may  be  coniparatively  mild,  at  another  alarmingly  severe. 
It  may  reappear  as  a  widespread  epidemic  of  a  very  virulent 
type  in  localities  in  which  it  had  appeared  previously  in  only 
an  insignificant  way.  It  may  appear  in  several  occupants  of 
the  same  house,  or  in  persons  who  have  temporarily  resided 
in  the  same  house  with  one  sick  of  the  disease,  giving  rise  to 
the  opinion  that  it  is  transmitted  by  contagion.  On  the  other 
hand,  single  cases  often  occur  in  a  family,  the  members  of 
which  are  intimately  associated  with  one  another,  and  all 
others  may  escape.  It  has  appeared  in  a  house,  disappeared 
for  a  time,  and  reappeared. 

Age,  Social  Condition,  Season,  Mortality,  etc. — 
Epidemic  cerebrospinal  meningitis  is  a  disease  of  cliildhood 
and  earl)-  adult  life.  It  is  rare  before  one  year,  and  gradually 
diminishes  in  frequency  after  thirty  years  of  age.     Though 


EPIDEMIC   CEREBROSPINAL    MENINGITIS.  121 

the  concomitants  of  poverty  usually  seem  to  predispose  to 
the  disease,  there  is  abundant  evidence  to  demonstrate  that 
these  conditions  are  not  essential  to  its  causation.  In  the 
recent  epidemic  in  Boston,  for  instance,  the  cases,  with  the 
exception  of  a  limited  area  along  the  water-front,  were  pretty 
evenly  distributed  throughout  both  the  poorer  and  better 
parts  of  the  city. 

It  is  a  disease  of  late  winter  and  early  spring.  It  has  been 
known  to  disappear  with  the  onset  of  warm  weather ;  it  has 
been  known  to  make  its  appearance  in  warm  weather.  Pro- 
longed rain  is  thought  by  some  to  favor  it.  Excessive  cold 
is  thought  by  others  to  favor  it.  Available  evidence  does  not 
justify  the  opinion  that  atmospheric  conditions  per  se  have 
or  have  not  anything  to  do  with   its  advent. 

The  mortality  varies  according  to  the  severity  of  the  epi- 
demic from  25  to  70  per  cent,  of  all  affected.  In  the  Boston 
outbreak  of  1896- 1897,  68.5  per  cent,  of  the  iii  cases  seen 
in  three  hospitals  proved  fatal.  Rollet,  in  presenting  the 
statistics  on  this  point  for  all  epidemics  in  France  up  to  the 
year  1884,  records  seven  in  which  the  mortality  was  less 
than  50  per  cent,  and  nine  in  which  it  was  above  50  per 
cent. ;  in  the  former  group  the  lowest  mortality  was  28  per 
cent,  in  the  latter  the  highest  was  75  per  cent. 

Hirsch  states  that  the  disease  is  more  common  among 
negroes  than  whites,  but  he  is  inclined  to  regard  this  as  due 
less  to  racial  peculiarity  than  to  social  conditions. 

It  is  a  disease  of  subtropical  and  temperate  climates,  and 
is,  according  to  Hirsch,  unknown  in  the  tropics  and  rare  in 
colder  regions. 

Portals  of  Infection,  Modes  of  Dissemination,  etc. 
— When  we  remember  that  the  essential  lesion  of  the  dis- 
ease is  enclosed  within  bony  cavities  and  that  it  is  usually 
confined  to  the  tissues  in  these  cavities,  it  is  evidently 
difficult  to  offer  any  satisfactory  opinion  as  to  the  channels 
through  which  primary  infection  took  place,  or  those  through 
which  the  specific  micro-organism  may  be  eliminated  from 
the  diseased  person,  both  points  being  requisite  to  an  accu- 


122  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

rate  undcrstandinij  of  the  phases  of  the  subject  under  con- 
sideration. 

There  can  be  no  doubt  that  infection  occurs  from  without ; 
that  the  infective  matters  are  carried  to  the  meninges  through 
either  blood  or  lymphatic  channels  or  both ;  but  whether  it 
enters  the  body  through  the  alimentary  or  respiratory  tracts 
or  through  superficial  wounds  it  is  not  possible  to  say. 

In  severe  epidemics  fatal  results  occur  so  quickly  after  the 
onset  of  the  disease  that  in  many  cases  there  is  no  involve- 
ment of  other  organs  than  those  within  the  cranium  and 
spinal  canal,  and  the  specific  micro-organism  is  confined  to 
these  localities.  It  is  hardly  conceivable,  therefore,  that  these 
cases  serve  as  sources  from  which  attendants  or  other  indi- 
viduals in  association  with  the  sick  may  contract  the  disease. 
In  a  certain  proportion  of  cases  there  is  secondary  involve- 
ment of  other  organs  that  communicate  more  freely  with  the 
surface  of  the  body — /.  c.  secondary  pneumonia,  middle-ear 
inflammations,  and  involvement  of  special  organs  and  of  mu- 
cous and  serous  surfaces  may  be  encountered.  If  the  dis- 
ease is  really  transmissible  from  person  to  person,  it  is  prob- 
ably this  group  of  cases  that  is  most  favorable  to  it.  It 
must  be  said,  however,  that  the  bulk  of  evidence  does  not 
lead  to  the  opinion  that  epidemic  cerebrospinal  meningitis  is 
a  directly  contagious  disease,  or  that  it  is  often  carried  from 
the  sick  to  the  well  by  fomites.  The  history  of  numerous 
outbreaks  leads  more  to  the  opinion  that  the  cases  are  in- 
fected from  some  common  source,  and  that  they  are  predis- 
posed to  such  infection  by  some  unusual  local  condition. 
This  opinion  is  supported  by  the  peculiarity  of  the  epidemic 
outbreak  of  this  disease  as  noted  above — namely,  that  it 
shows  no  special  tendency  to  progress  along  continuous  lines 
or  through  contiguous  localities.  It  may  appear  suddenly  in 
a  locality,  and  as  suddenly  disappear  to  reappear  almost  at 
once  in  some  remote  district.  It  has  been  known  to  appear 
in  two  regiments  in  camp,  while  a  third,  located  between  the 
infected  regiments,  escaped.  Love  states  that  at  New  Orleans 
in  1847,  the  disease  attacked  one  regiment  which  was  quar- 
tered in  poor  barracks  on  damp  soil,  and  supplied  with  poor 


EPIDEMIC   CEREBROSPINAL    MENINGITIS.  1 23 

clothing,  while  an  adjacent  regiment,  more  favorably  housed 
and  clothed,  escaped  entirely.  The  history  of  the  disease  is 
characterized  throughout  by  irregularities  in  the  manner  of 
its  occurrence  and  the  conditions  under  which  it  has  made  its 
appearance.  At  times  it  has  prevailed  in  rural  districts,  the 
cities  remaining  comparatively  free,  while  again  the  reverse 
has  been  the  case. 

Prophylaxis. — From  what  has  been  said,  it  is  manifestly 
impossible  to  outline  a  rational  scheme  of  prophylaxis  against 
this  disease.  We  lack  what  underlies  all  such  systems — 
namely,  precise  knowledge  of  the  manner  of  infection  and  the 
channels  of  dissemination  of  this  malady. 

Since  it  is  improbable  that  the  disease  is  transmissible  from 
person  to  person,  rigid  isolation  of  the  sick  is  not  generally 
regarded  as  imperative.  In  the  protracted  cases,  especially 
those  with  secondary  involvements,  the  discharges  and  ex- 
creta should  be  disinfected  as  soon  as  passed.  The  dead 
should  be  disposed  of  by  burial  or  cremation  as  soon  after 
death  as  decency  and  circumstances  will  permit. 

Since  the  evidence  leads  us  to  regard  the  occurrence  of  the 
disease  as  favored  frequently  by  local  predisposing  conditions, 
such  as  bad  hygienic  environment  in  general,  too  much  care 
cannot  be  given  to  the  sanitation  of  the  house,  personal 
hygiene,  and  those  measures  that  prevent  infection  by  way  of 
food  and  drink. ^ 

1  Read  Hirsch  :  Pathologische  Geoi^raphie,  Bd.  iii.,  S.  379  ;  Councilman, 
Mallory,  and  Wright :  Epidemic  Cerebrospinal  Meningitis  and  its  Relation  to 
other  Forms  of  Mejiingitis ;  a  Report  of  the  State  Board  of  Health,  Mass., 
1898  ;  Stille  :   System  of  Medicine,  vol.  i.,  1885. 


124  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 


INFLUENZA. 

Cause. — Influenza  is  an  infectious  catarrhal  process  in 
^\-hich  the  causative  micro-organism,  probably  bacillus  infiii- 
cnzce,  is  localized  in  the  respiratory  tract.  The  accompany- 
ing constitutional  manifestations  are  apparently  of  toxic 
origin,  resulting  from  the  absorption  by  the  blood  of  toxins 
produced  by  the  growing  bacilli  in  bronchial  mucous  mem- 
branes. The  bacillus  of  influenza  is  a  very  small,  non-motile, 
non-spore-bearing,  non-liquefying  rod  that  is  constantly  to  be 
found  in  the  sputum  of  individuals  suffering  from  influenza. 
It  stains  less  readily  with  the  ordinary  basic  anilin  dyes  than 


Fig.  12. — Bacillus  influenzae  in  sputum. 

do  other  bacteria.  It  does  not  stain  by  Gram's  method.  It 
may  be  isolated  in  pure  culture  from  the  sputum  of  influenza 
patients.  It  cannot  be  readily  cultivated  on  the  ordinary 
nutrient  media.  It  grows  only  at  body-temperature  and  upon 
the  surface  of  media  over  which  has  been  distributed  either 
blood  or  blood-coloring  matter.  The  coloring  matter  of  the 
blood  appears  to  afford  substances  especially  adapted  to  the 
nutrition  of  this  organism.  Its  colonies  appear  as  very 
minute,  discrete,  colorless  points  of  growth  that  have  some- 
what the  appearance  of  small  drops  of  dew. 


INFLUENZA.  12$ 

It  is  extremely  sensitive  to  drying,  withstanding  the  process 
at  20°  C.  for  but  little  over  twenty-four  hours. 

The  results  of  inoculation  of  animals  with  cultures  of  this 
organism  indicate  that  under  these  circumstances  its  path- 
ogenesis depends  more  upon  toxic  than  upon  actively  infec- 
tive properties. 

Occurrence,  Distribution,  etc.  —  Influenza  appears 
usually  in  an  epidemic  form,  having  its  origin  in  some  one 
locality  or  another  and  travelling  with  great  rapidity,  often  as 
a  true  pandemic,  over  the  major  part  of  the  inhabited  earth's 
surface. 

According  to  Hirsch,  the  first  trustworthy  literary  records 
of  the  disease  date  from  the  early  part  of  the  twelfth  century. 
Between  1 173  and  1874  it  made  its  appearance  on  eighty-six 
different  occasions.  Its  first  recorded  occurrence  in  the 
United  States  was  in  Massachusetts  in  the  summer  of  1627; 
since  that  time  it  has  visited  this  country  with  varying 
degrees  of  severity  twenty-two  times.  The  last  pandemic, 
that  of  1 889-1 890,  appears  to  have  originated  in  Central 
Asia  and  to  have  spread  thence  to  Russia,  Germany,  France, 
England,  and  finally  to  North  America.  Its  occurrence 
does  not  seem  to  be  influenced  by  climate,  season,  geological 
or  geographical  conditions.  The  ideas  regarding  the  peri- 
odicity of  its  visitations,  and  that  relating  to  the  fixity  of  the 
direction  of  its  spread  from  east  to  west,  receive  no  support 
from  Hirsch's  analysis  of  the  various  epidemics.  Neither 
race,  sex,  nor  age  appears  to  serve  as  an  important  predis- 
posing factor. 

Dissemination. — It  is  impossible  to  say  what  the  condi- 
tions are  that  favor  its  development  and  spread.  Its  dissemi- 
nation over  large  areas  is  often  so  rapid  as  hardly  to  admit 
of  the  explanation  that  it  is  carried  from  place  to  place  by 
travellers  or  through  merchandise.  The  fact  that  the  organ- 
ism which  is  believed  to  be  its  cause  is  quickly  destroyed  by 
drying  contraindicates  in  a  measure  the  opinion  that  the 
virus  is  transported  from  one  locality  to  another  by  winds. 
Undoubtedly  the  spread  of  the  disease  is,  in  part  at  least, 
accomplished  through  infected  travellers.     Our  knowledge  is 


126  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

not  sufificient  to  allow  of  the  statement  that  it  is  directly 
transmissible  from  individual  to  individual,  but  a  great  deal 
of  circumstantial  evidence  points  to  this  as  being  the  case. 

Mode  of  Infection. — On  this  point  also  our  information 
is  but  meagre,  and  it  can  only  be  said  that  in  all  likelihood 
infection  occurs  through  the  respiratory  tract. 

Prophylaxis  should  consist  in  careful  attention  to  the 
hygiene  of  the  person,  the  avoidance  of  all  influences  that 
tend  to  lower  the  general  tone  of  the  tissues  and,  in  so  far  as 
is  possible,  non-communication  with  individuals  already 
affected  with  the  disease.  The  invasion  of  the  malady  is 
usually  so  subtle  that  prophylactic  measures  are  of  but  little 
avail. 

The  handkerchiefs,  napkins,  eating  utensils,  and  the  sputum 
of  influenza  patients  should  be  scalded  before  they  are  taken 
from  the  sick-room. 

When  we  remember  how  great  a  number  of  cases  in  any 
epidemic  of  this  disease  are  not  confined  to  the  house,  it  is 
manifest  that  elaborate  prophylactic  measures  can  be  opera-" 
tive  against  only  a  part  of  those  sick.  The  walking  cases 
cannot  be  brought  under  control ;  these  may  be  and  prob- 
ably are  the  most  important  disseminators  of  the  infective 
materials. 


BUBONIC  PLAGUR 

Definition,  Cause,  etc. — An  acute,  specific,  contagious  (?) 
disease  that  is  characterized  by  inflammation,  and  in  many 
cases  by  suppuration  of  the  lymphatic  glands,  especially 
those  of  the  inguinal,  axillary,  cervical,  and  submaxillar)' 
regions.  It  is  attended  with  great  mortality.  According  to 
Ycrsin,  the  death-rate  among  hospital  cases  during  the  late 
epidemic  in  China  was  about  95  per  cent.  The  investigations 
of  Yersin  and  of  Kitasato  point  to  a  specific  micro-organism 
as   the   exciting   cause,  while   all  writers   are  at   one  in   the 


BUBONIC  PLAGUE.  12/ 

opinion  that  the  most  predisposing  causes  are  the  common 
concomitants  of  extreme  poverty — namely,  overcrowding, 
filth,  bad  air,  poor  food,  and  intemperance. 

The  organism  discovered  by  Yersin  and  by  Kitasato  in 
cases  of  the  disease  examined  by  them  during  the  epidemic 
at  Hong  Kong  in  1894,  is  described  as  a  short,  oval,  cap- 
sulated,    actively    motile,    non-spore-bearing,    polar-staining 


Fig.  13. — Pus  from  bubo  in  bubonic  plague ;  showing  the  specific  micro- 
organism. 

bacillus.  It  is  present  in  large  numbers  in  the  suppurating 
glands,  and  in  smaller  numbers  in  the  blood. 

It  stains  with  the  ordinary  anilin  dyes,  taking  up  the  color 
more  intensely  at  its  ends  than  at  its  middle  portion.  It  is 
decolorized  by  Gram's  method  of  staining. 

It  grows  luxuriantly,  without  liquefaction,  on  solidified 
blood-serum,  as  a  yellowish-gray  deposit.  It  may  also  be 
isolated  on  agar-agar,  especially  when  glycerin  has  been 
added.  It  does  not  cause  uniform  clouding  of  the  bouillon, 
but  grows  in  shred-like  clumps  that  adhere  to  the  sides  or 
sink  to  the  bottom  of  the  tube.  The  temperature  most  favor- 
able to  its  growth  is  between  36°  and  39°  C. 

It  is  destroyed  in  four  days  by  drying  at  the  ordinary  tem- 
perature of  the  room.  Direct  sunlight  kills  it  in  from  three 
to   four  hours.     It  is   killed  in  a  few  minutes  by  steam  at 


128  nVGIEXE    OF   TRANSMISSIBLE   DISEASES. 

ioo°  C,  and  in  half  an  hour  by  8o°  C.  It  is  destroyed  by  an 
exposure  of  two  hours  to  carboHc  acid,  in  0.5  per  cent,  soki- 
tion,  and  to  milk  of  lime  in  i  per  cent,  solution. 

Rabbits,  guinea-pigs,  rats,  mice,  and  sheep  are  susceptible 
to  subcutaneous  inoculation  with  the  plague  bacillus.  Pigeons 
are  immune.  The  lesions  found  at  autopsy  in  animals  dead 
after  inoculation,  either  with  cultures  of  this  organism  or  with 
pus  from  a  suppurating  gland,  while  not  apparently  identical 
with  those  seen  in  the  human  cadaver,  do  nevertheless  pre- 
sent certain  features  that  may  be  considered  as  in  part  a 
reproduction  of  the  disease — namely,  the  marked  involve- 
ment of  the  lymphatic  apparatus.  The  organism  is  found  in 
the  internal  organs  of  animals  dead  from  inoculation. 

Distribution,  Race,  Season. — Our  knowledge  of  this 
historic  pestilence  dates  from  about  the  end  of  the  first  cen- 
tury of  the  Christian  era.  Its  home  was  for  centuries  sup- 
posed to  be  Northern  Africa.  During,  and  for  a  period  after, 
the  Middle  Ages,  it  was  more  or  less  frequently  prevalent  in 
epidemic  form  in  Asia  Minor,  China,  India,  Egypt,  Arabia, 
Northern  Africa,  Italy,  France,  Germany,  and  throughout 
other  parts  of  Europe.  It  appeared  in  Europe  for  the  first 
time  during  the  reign  of  Justinian  in  the  sixth  century  of  the 
present  era.  Beginning  in  Egypt  in  542  A.  D.,  it  passed 
during  the  next  year  to  Constantinople  and  thence,  during 
the  remaining  half  of  the  sixth  century,  it  spread  over  pretty 
much  the  whole  of  the  Roman  world.  Ten  thousand  people 
are  said  to  have  died  of  it  in  a  single  day  in  Constantinople. 
Omitting  the  numerous  outbreaks  that  occurred  in  the  mean- 
time, we  encounter  the  historic  visitation  of  the  fourteenth 
century — the  "  Black  Death  " — which,  according  to  Haecker, 
proved  fatal  to  about  25,000,000  people — a  quarter  of  the 
entire  population  of  Europe.  During  its  prevalence  at  Oxford 
in  1352,  two-thirds  of  the  academic  j)opulation  are  said  to 
have  succumbed. 

There  is  a  controversy  among  writers  as  to  whether  the 
"  Black  Death  "  was  an  uncomplicated  epidemic  of  bubonic 
plague  or  not.  It  appears  that  a  part  of  the  mortality  may 
have  been  due  to  malignant  typhus  fever,  a  part  to  the  so- 


BUBONIC  PLAGUE.  1 29 

called  plague  of  India,  and  a  part  to  true  bubonic  plague. 
The  unsanitary  and  social  conditions  of  the  people  at  that" 
time  were  equally  predisposing  to  either  one  of  these  pes- 
tilences. 

During  the  "  Great  Plague  of  London  "  (1664-65)  the  total 
mortality  for  one  year  was  68,596  out  of  an  estimated  popu- 
lation of  460,000,  of  whom  two-thirds  are  supposed  to  have 
fled  to  escape  the  contagion.  The  mortality  rose  during  this 
epidemic  from  43  in  May  to  590  in  June,  6137  in  July,  17,036 
in  August,  and  31,159  in  September,  after  which  there  was  a 
decline.  There  was  an  epidemic  of  "  spotted  fever  "  at  the 
same  time  in  London. 

Though  Northern  Africa  is  considered  the  home  of  the 
plague,  it  is  interesting  to  note  that  the  disease  has  now  ex- 
tended into  the  southern  part  of  that  continent.  It  has  never 
been  known  to  cross  the  plains  of  India.  It  has  never  visited 
America. 

The  mortality  from  bubonic  plague  varies  in  different  epi- 
demics from  53  to  95  per  cent. 

Race  appears  to  have  less  predisposing  influence  than  does 
social  condition.  It  is  a  disease  preeminently  of  the  poor 
and  destitute,  its  existence  and  spread  being  favored  by  the 
manifold  unhealthy  conditions  under  which  this  class  of 
society  exists. 

During  the  recent  epidemic  at  Hong  Kong,  China,  the 
deaths  were  distributed  according:  to  sex  and  aee  as  follows  : 


Men 62.40  per  cent. 

Women 19.23        " 

Boys 8.92        " 

Girls 9.45        " 


Telluric  conditions  seem  to  have  but  little  influence  upon 
the  existence  of  plague,  as  it  has  occurred  in  alluvial  deltas, 
along  calcareous  ridges,  and  on  granitic  mountains.  Nor  is 
it  apparently  controlled  by  altitude,  for  epidemics  have  oc- 
curred both  along  the  low-lying  borders  of  rivers,  as  along 
the  Nile,  the  Euphrates,  the  Volga,  and  the  Thames,  and  in 
9 


130  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

the  mountains  of  India  and  Kurdestan,  at  elevations  of  from 
5000  to  7000  feet  above  the  sea. 

The  disease  seldom  occurs  in  the  tropics.  Season  has  ap- 
parently no  definite  effect  upon  it.  It  has  been  seen  to 
appear  and  to  diminish  and  disappear  during  both  hot  and 
cold  weather. 

Dissemination  and  Modes  of  Infection. — Plague  has 
arisen  so  uniformly  in  unclean  places  that  filth  is  generally 
regarded  as  the  most  potent  factor  in  favor  of  its  origin  and 
spread.  Almost  without  exception,  plague-centers  have  been 
characterized  by  a  soil  polluted  with  decomposing  animal 
matters,  and  by  overcrowding  of  destitute,  dirty,  and  poorly- 
nourished  people.  An  interesting  and  important  fact  that 
points  to  the  soil  as  the  location  of  the  plague-virus  is  the 
observation  that  usually  during,  and  often  preceding,  the  ap- 
pearance of  the  disease  among  human  beings  there  is  an  epi- 
demic of  plague  among  rats,  mice,  and  swine,  particularly 
rats  and  mice. 

During  the  recent  epidemic  in  Hong  Kong  the  locality 
most  affected  by  the  disease  had  a  Chinese  population  equiv- 
alent to  21,618  souls  per  acre  of  house-area.  The  mean 
size  of  the  main  room  of  a  house  in  this  neighborhood  was 
26  by  14  feet  by  10  feet  high ;  such  a  room  served  as  living- 
space  for  from  16  to  25  people.  The  personal  habits  of  the 
occupants  are  described  as  filthy  beyond  belief,  cleanliness  or 
anything  akin  to  it  being  apparently  an  unknown  art. 

Opinion  is  divided  as  to  whether  the  contagion  of  plague 
is  disseminated  through  the  air.  It  may  be  spread  by  means 
of  infected  clothing  and  other  objects  that  have  been  in  use 
by  the  patient.  It  does  not  seem  to  be  carried  from  place  to 
place  by  means  of  merchandise.  It  is  most  often  dissem- 
inated from  places  in  which  it  is  either  endemic  or  epidemic 
to  other  localities,  through  human  intercourse.  It  is  improb- 
able that  the  disease  is  spread  to  any  great  extent  through 
the  use  of  infected  water  or  food. 

As  a  result  of  his  investigations  at  Hong  Kong,  Aoyoma 
expresses  the  opinion  that  in  the  great  majority  of  cases,  if 
not  in  all,  dissemination  of  the  plague  occurs  through  the  in- 


BUBONIC  PLAGUE.  I3I 

fection  of  skin-wounds,  and  much  less  frequently  than  has 
been  supposed  by  way  of  the  respiratory  and  alimentary 
tracts.  He  points  out  that  during  the  epidemic  physicians 
and  nurses  who  were  in  attendance  upon  infected  individuals 
and  who  spent  much  of  their  time  in  places  where  the  sick 
were  lodged,  rarely  became  affected  ;  and,  further,  of  300 
Enghsh  soldiers  who  volunteered  to  clean  and  disinfect  the 
pest-houses,  only  10  contracted  the  disease. 

This  opinion,  with  the  character  of  the  evidence  in  support 
of  it,  coincides  with  that  of  a  number  of  observers  who  have 
studied  the  course  of  the  disease  in  other  localities.  Aoyoma 
does  not  regard  it  as  probable  that  an  actual  pest  atmosphere 
exists,  an  opinion  at  variance  with  that  of  a  number  of  other 
writers  who  insist  that  prolonged  breathing  of  the  air  about 
a  plague  patient  is  one  of  the  certain  ways  of  contracting  the 
disease ;  at  the  same  time  they  admit  that  the  casual  entrance 
into  a  room  occupied  by  such  patients  does  not  often  result 
in  infection. 

Prophylaxis. — The  most  important  safeguards  against 
the  generation  and  spread  of  plague  are  personal  cleanliness, 
the  removal  of  organic*  waste  from  about  the  dwellings,  good 
drainage  of  the  soil,  and  the  prevention  of  overcrowding. 

When  the  disease  first  makes  its  appearance  in  a  house, 
the  sick  should  be  at  once  removed  to  a  hospital  and  there 
isolated.  The  healthy  members  of  the  household  should  be 
quarantined  and  kept  under  observation  for  from  ten  days  to 
two  weeks.  In  the  meantime  the  house  should  be  thor- 
oughly cleaned  and  disinfected.  The  ceiling,  walls,  floor, 
and  all  other  surfaces  should  be  scrubbed  with  a  3  per  cent, 
carbolic-acid  or  a  i  :  1000  corrosive-sublimate  solution.  The 
furniture  of  the  sick  should  be  scrubbed  with  a  3  per  cent, 
solution  of  carboHc  acid  in  warm  water,  and  body-  and  bed- 
clothing  should  be  steamed  for  one  hour  at  100°  C. ;  all 
articles  of  little  value  that  have  been  about  the  patient  should 
be  burned.  With  regard  to  the  precautions  to  be  taken 
while  in  attendance  upon  the  sick,  it  should  be  borne  in  mind 
that  the  discharges  from  suppurating  buboes,  and  possibly 
the  discharges  from  the  bowels  or  the  stomach,  are  infective. 


132  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

All  objects,  therefore,  that  have  been  soiled  with  such  mat- 
ters should  be  boiled  or  steamed  at  ioo°  C.  before  beino-  re- 
moved  from  the  sick-room. 

Since  infection  most  often  occurs  through  abrasions  of  the 
skin,  care  should  be  taken  that  infective  materials  do  not 
come  in  contact  with  wounds,  scratches,  etc.,  of  the  hands. 
The  hands  should  be  carefully  disinfected  after  the  necessary- 
manipulations  of  the  patient.  The  great  frequency  with  which 
the  deep  glands  of  the  groin  were  the  first  to  become  in- 
flamed, during  the  late  epidemic  in  Hong  Kong,  is  explained 
by  the  fact  that  the  Chinese  of  the  poorer  classes  wear  no 
shoes,  and  the  virus  gained  entrance  to  the  lymphatics,  pass- 
ing directly  to  these  glands  through  small  wounds  of  the  skin 
of  the  feet.  In  this  epidemic  (as  in  others)  the  soil  was  mani- 
festly infected. 

Those  who  die  of  the  disease  should  be  wrapped  in  a 
sheet  soaked  in  a  i  :  lOOO  corrosive-sublimate  or  5  per  cent, 
carbolic-acid  solution,  and  either  buried  or  cremated  at  once. 

Those  who  recover  should  be  kept  in  quarantine  under 
medical  observation  for  at  least  a  month.  Kitasato  has 
found  the  bacillus  of  plague  in  the  blood  of  a  patient  as 
long  as  three  weeks  after  the  beginning  of  convalescence. 

Incoming  ships  from  plague-infected  ports  should  be  sub- 
ject to  quarantine  for  a  time  sufficient  to  permit  of  thorough 
medical  inspection.  If  found  to  be  infected,  the  sick  should 
be  removed  to  hospital  and  the  healthy  members  of  the 
crew  isolated.  The  ships  should  then  be  thoroughly  disin- 
fected. In  short,  they  should  be  treated  the  same  as  an 
infected  house  (see  above). 

There  is  some  question  as  to  the  propriety  of  preventing 
the  free  migration  of  uninfected  people  from  a  place  in  which 
plague  prevails  to  localities  that  are  free  from  it.  Such  emi- 
gration enables  many  to  escape  the  pestilence,  and  the  danger 
of  their  introducing  the  disease  into  their  new  abode  may  be 
eliminated  by  a  quarantine  of  sufficient  time  (from  seven  to 
ten  days)  to  demonstrate  that  none  of  them  are  already 
afflicted  with  plague.  If,  after  such  detention,  careful  med- 
ical inspection,  and  thorough  disinfection  of  their  clothing  and 


SUPPURATIVE   AND   SEPTIC  INFECTIONS.  I  33 

other  belongings  no  cases  of  the  disease  are  found,  these 
individuals  may  with  reasonable  safety  be  permitted  to  mingle 
with  the  general  public. 


SUPPUFLA.TIVE  AND  SEPTIC  INFECTIONS. 

Under  this  head  may  properly  be  included  the  ordinary 
suppurative  troubles  resulting  from  infection  by  the  com- 
mon pyogenic  cocci — such,  for  example,  as  boils,  abscesses, 
phlegmons,  etc. ;  those  conspicuous  for  their  migratory  ten- 
dency, and  which  are  usually  due  to  a  particular  species  of 
pyogenic  cocci,  notably  erysipelas,  lymphangitis,  etc. ;  and 
those  general  infections  that  partake  of  the  nature  of  septi- 
cemia and  pyemia,  and  which  may  or  may  not  be  referable  to 
the  common  pyogenic  cocci. 

The  treatment  of  these  conditions  together  is  thought 
advisable,  not  because  of  etiological  or  clinical  relationship, 
but  rather  because  of  their  common  characteristics  when 
viewed  from  the  standpoint  of  prevention. 

The  acute,  circumscribed,  inflammatory  processes  most 
frequently  result  from  the  activities  of  the  ordinary  pus-pro- 
ducing cocci,  the  most  common  of  which  is  stapliylococcus 
pyogenes  aureus  (Fig.  14). 

This  organism  is  a  micrococcus  that  develops  in  the  form 
of  irregular  clusters.  Its  designation  "  aureus  "  signifies  that 
its  growth  is  characterized  by  a  golden  or  orange  color.  It 
liquefies  gelatin,  coagulates  milk,  and  on  both  nutrient  agar- 
agar  and  potato  grows  as  a  yellow  or  orange-colored  deposit. 
It  grows  at  ordinary  room-temperature,  but  better  at  the 
temperature  of  the  body.  It  is  tenacious  of  life,  and  with- 
stands drying  for  months.  In  old  cultures  it  has  been  known 
to  retain  its  virulence  for  as  long  as  a  year.  It  is  destroyed 
in  ten  minutes  by  a  temperature  of  62°  C.  It  does  not  form 
spores,  though  it  is  usually  regarded  as  one  of  the  resistant 


134  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

cocci,  for  the  reason  that  it  does  not  readily  succumb  to  those 
influences  that  prove  detrimental  to  most  of  the  non-spore- 
bearing  pathogenic  bacteria.  In  addition  there  are  other 
varieties  of  staphylococci  that  are  associated  with  circum- 
scribed inflammatory  conditions.  They  are  markedly  less 
pathogenic  than  the  organism  just  mentioned.  They  are 
designated  by  names  indicative  of  the  color  of  their  colonies, 


Fig.  14.— Pus  showing  presence  of  staphylococcus  pyogenes  aureus. 

as  seen  under  artificial  cultivation — viz.,  staphylococcus  pyo- 
genes citrcns,  lemon-yellow  colonies  ;  staphylococcus  pyogenes 
albus,  white  colonies  ;  staphylococcus  cpidcrniidis  albus,  a  sta- 
phylococcus frequently  present  in  the  epidermis  and  grow- 
ing with  white  colonies. 

By  particular  methods  of  inoculation  suppurative  lesions 
similar  to  those  observed  in  man  may  be  produced  in  animals 
through  the  employment  of  cultures  of  staphylococcus  pyo- 
genes aureus.  In  man  this  organism  is  the  cause  of  a 
variety  of  inflammatory  conditions,  notably  boils,  abscesses, 
phlegmons,  osteomyelitis,  meningitis,  acute  ulcerative  endo- 
carditis, peritonitis,  pleuritis,  synovitis,  etc.  In  fact,  there  is 
hardly  an  inflammatory  condition  in  which  it  has  not  at  one 
time  or  anotiier  played  the  etiological  role. 

Those  inflammations  having  a  migatory  or  spreading  ten- 
dency, though  also  sometimes  due  to  the  organism  just  men- 


SUPPURATIVE  AND   SEPTIC  INFECTIONS.  I  35 

tioned,  are  more  commonly  characterized  by  the  presence  of 
another  of  the  group  of  pyogenic  bacteria — namely,  strep- 
tococcus pyogenes  (Fig.  15),  identical  in  all  probability  with 
streptococcus  erysipelatis. 

This  organism  is  characterized  by  its  growth  in  chains — 
i.  e.,  it  divides  transversely  in  one  direction  of  space,  the 
daughter-cells  having  the  tendency  to  adhere  together  like 
strands  of  beads.     It  does  not  grow  luxuriantly  under  arti- 


FlG.  15. — Pus  from  erysipelas,  showing  presence  of  streptococcus  pyogenes. 

ficial  cultivation,  its  colonies  ordinarily  being  hardly  more 
than  very  small  points.  Its  growth  is  not  accompanied  by 
the  production  of  color.  It  does  not  liquefy  gelatin,  and  in 
transparent  fluid  media  does  not  cause  diffuse  clouding,  but 
grows  rather  in  thread-like  clumps  that  cling  to  the  sides  and 
sink  to  the  bottom  of  the  tube.  It  grows  at  ordinary  room- 
temperature  and  at  that  of  the  body.  It  is  not  readily  destroyed 
by  drying,  and  has  been  detected  on  several  occasions  in  the 
dust  and  in  the  air  of  hospital  wards  that  have  been  occupied 
by  patients  suffering  from  infections  in  which  it  was  present. 
It  is  killed  in  ten  minutes  by  from  52°  to  54°  C.  (Sternberg), 
It  is  conspicuous  for  the  variability  of  its  virulence.  Cultures 
are  rarely  encountered,  even  in  those  fresh  from  diseased  tis- 
sues, that  exhibit  marked  disease-producing  properties  in 
animals.     At  times  it  is  capable,  on  inoculation,  of  causing 


136  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

general  infection,  while  again  the  result  may  be  a  local  ab- 
scess or  an  erysipelatous  inflammation  about  the  site  of 
infection.  The  writer  has  encountered  a  culture  of  this 
organism  that  produced,  when  injected  into  the  circulation 
of  rabbits,  diffuse  miliary  abscess-formations  in  the  muscles, 
similar  histologically  to  those  caused  under  the  same  circum- 
stances by  stapJiylococais  aureus ;  while,  on  the  other  hand, 
when  rubbed  into  a  wound  of  the  ear  of  another  rabbit  a 
severe  erj'sipelas  resulted.  The  two  conditions  were  not 
observed  coincidently  in  the  same  animal. 

In  general,  this  organism  seems  to  be  much  more  patho- 
genic for  man  than  for  animals.  It  has  been  detected  in  a 
number  of  pathological  lesions  in  man,  among  which  may  be 
mentioned  erysipelas,  spreading  phlegmons,  ulcerative  endo- 
carditis, puerperal  peritonitis,  the  anginas  of  scarlatina  and  of 
measles,  pleuritis,  pericarditis,  pneumonia,  and  mixed  with 
the  diphtheria  bacillus  in  the  diphtheritic  false  membrane. 

The  general  infections  that  partake  of  the  nature  of  septi- 
cemia and  pyemia,  while  usually  due  to  the  ordinary  pyogenic 
bacteria,  are  not  always  to  be  referred  to  this  cause.  There 
is  now  a  general  consensus  of  opinion  that  under  peculiar 
predisposing  influences  a  number  of  different  organisms,  not 
usually  regarded  as  pyogenic,  may  find  conditions  favorable 
to  their  invasion  of  the  body  and  to  their  development  within 
the  circulating  fluids  and  in  the  tissues.  The  wider  applica- 
tion of  bacteriological  methods  to  the  study  of  septic  infec- 
tions has  brought  out  the  important  and  interesting  fact  that 
the  lesions  found  are  not  specifically  related  to  definite  bacte- 
rial species,  but  may,  under  circumstances  not  entirely  clear, 
result  from  the  activities  of  a  variety  of  different  species. 

The  predisposing  causes  which  favor  infection  by  any  of 
the  foregoing  pyogenic  species  of  bacteria  are  those  which 
generally  tend  to  depress  vitality,  viz. :  chronic  alcoholism, 
anemia,  I^right's  disease,  diabetes,  and  severe  burns. 

Recently  delivered  women  are  especially  prone  to  erysip- 
elas and  septic  infections. 

Modes  of  Dissemination. — The  causative  micro-organ- 
isms arc  ])rcscnt  in  greater  or  smaller  numbers  in  the   dis- 


SUPPURATIVE  AND   SEPTIC  INFECTIONS.  1 37 

charges  from  all  acute  inflammatory  processes.  The  pus 
from  old  foci  of  suppuration  is  sometimes  found  to  be  free 
from  living  bacteria,  though  the  remains  of  dead  micro- 
organisms may  often  be  detected  microscopically.  Under 
these  circumstances  the  causative  organisms  have  died  in  the 
products  of  their  own  pathogenic  activities. 

In  the  majority  of  cases  the  organisms  found  in  the  dis- 
charges from  acute  processes  are  living  and  capable  of  light- 
ing up  inflammatory  conditions  when  they  gain  access  to 
wounds.  When  dried  they  may  be  disseminated  through 
the  air  as  dust,  and  may  excite  suppuration  in  abraded  sur- 
faces on  which  they  may  fall,  though  this  is  not  now 
regarded  with  the  same  degree  of  apprehension  by  surgeons 
as  it  formerly  was.  The  modern  view  concerning  the  modes 
of  transmission  of  these  conditions  is  that  in  the  vast  majority 
of  cases  the  disease  results  from  direct  contact — that  is, 
through  the  use  of  unclean  and  infected  hands  and  instru- 
ments at  the  time  of  operation,  and  through  the  dressing  of 
healthy  wounds  with  unsterilized  materials.  In  the  case  of 
erysipelas  it  is  possible  that  the  infection  may  be  dissemi- 
nated from  the  patient  during  the  period  of  desquamation, 
the  specific  micro-organism  being  conveyed  by  means  of  the 
minute  particles  of  exfoliated  epidermis.  All  surgical  accesso- 
ries are  capable  of  carrying  infection,  when  not  rendered  free 
from  infective  matters  by  thorough  cleansing  and  disinfec- 
tion before  being  employed  on  fresh  wound-surfaces. 

Probably  the  most  common  mode  of  dissemination  for 
surgical  infections  is  through  the  operator,  his  assistants,  and 
nurses,  because  of  inattention  to  their  own  personal  condi- 
tion. Individuals  whose  duties  bring  them  frequently  in 
contact  with  matters  that  are  more  or  less  infective  may 
themselves  be  the  agents  for  carrying  such  infections,  unless 
rigorous  attention  be  given  to  the  most  thorough  personal 
cleanliness  and  to  careful  disinfection  of  the  hands  before 
manipulating  non-infected  cases. 

Both  the  local  and  general  types  of  surgical  infection  may 
and  often  do  follow  apparently  insignificant  wounds  with 
infected  objects.      So    slight  an  injur)%  for  instance,  as  the 


138  HYGIEXE    OF   TKANSMISSIBLE   DISEASES. 

scratch  of  an  infected  pin,  or  the  prick  of  an  autopsy-scalpel, 
or  of  an  instrument  used  during  the  examination  of  such 
virulent  matters  as  the  exudate  of  a  septic  peritonitis,  have 
resulted  in  a  serious  and  sometimes  fatal  general  infection. 

Portals  of  Infection. — Open  wounds,  superficial  abra- 
sions, and  excoriations  of  mucous  surfaces  are  the  com- 
mon portals  of  infection.  Wounds  in  which  there  has  been 
much  insult  to  the  integrity  of  the  tissues,  and  much  inter- 
ference with  local  nutrition  (circulation),  are  particularly 
liable  to  suppurative  complications.  The  results  of  wound- 
infections  are  not  necessarily  limited  to  the  primary  site  of 
invasion.  Through  the  dissemination  of  infective  particles 
from  the  point  of  their  entry  by  way  of  the  blood  or  lymph- 
channels,  infection  may  become  general,  or  may  occur  sec- 
ondarily as  an  isolated  focus  in  some  one  or  another  of  the 
more  remote  internal  viscera. 

It  does  not  follow  that  every  wound  which  has  been 
exposed  to  infection  necessarily  becomes  infected.  In  many 
cases  the  weapons  of  defence  provided  by  nature  (vital 
tissue-resistance)  prove  to  be  of  sufficient  vigor  to  overcome 
the  invading  organisms,  in  which  event  primary  healing 
without  infection,  or  with  infection  to  but  an  inconsiderable 
degree,  occurs  ;  on  the  other  hand,  infection  occurs  when 
the  weapons  of  offence  possessed  by  the  invading  bacteria 
are  potent  to  paralyze  the  usual  vital  activities  of  the  tissues. 
The  process  of  infection  must  always  be  viewed  as  a  contest 
between  pathogenic  bacteria  on  the  one  side,  with  the  toxic 
products  of  their  growths  as  weapons  of  offence,  and  the 
tissues  on  the  other,  resisting  with  whatever  degree  of 
natural  vital  energy  the  circulating  fluids  and  cellular  ele- 
ments may  be  endowed.  All  agencies,  therefore,  that  in  any 
way  tend  to  depress  this  natural  vital  energy  of  the  tissues, 
either  through  their  local  or  their  constitutional  mode  of 
action,  deprive  them  of  their  only  mode  of  defence  and  ren- 
der them  liable  to  infection. 

Prophylaxis. — The  prophylactic  measures  that  arc  of 
most  avail  in  preventing  wound-infection  are  cleanliness  and 
protection  of  the  injured  tissues  from  infection  from  v/ithout 


SUPPURATIVE   AND   SEPTIC  INFECTIONS.  1 39 

during  the  process  of  repair.  These  procedures  find  their 
field  of  greatest  usefulness  in  hospitals  and  dispensaries, 
where  numbers  of  individuals  suffering  from  injuries  and 
from  various  surgical  infections  are  congregated  together. 

Without  discussing  the  details  of  antiseptic  technic  as 
practised  by  surgeons,  it  will  suffice  here  simply  to  indicate 
the  cardinal  points  to  be  kept  in  mind  in  the  prevention  of 
the  diseases  included  in  this  category. 

The  hands  should  always  be  thoroughly  washed  and  dis- 
infected, after  examining  an  infected  wound,  before  proceed- 
ing to  manipulate  other  wounds  either  infected  or  fresh.  The 
instruments  employed  should  have  been  thoroughly  cleaned 
by  washing  and  wiping,  and  then  disinfected — as  good  a 
method  of  disinfection  as  any  other  is  to  boil  them  for  ten 
minutes  in  a  2  per  cent,  sodium-carbonate  solution.  During 
the  operation  or  at  the  dressing  the  alkaline  solution  should 
be  rinsed  from  the  instruments  with  sterilized  distilled  water 
before  they  are  used  about  the  tissues.  All  ligatures  (not 
those  of  animal  tissue,  such  as  catgut),  sutures,  and  bandages 
should  be  sterilized  by  steam  before  using.  They  should  not 
be  removed  from  the  sterilizer  until  needed. 

Bandages  and  dressings  that  are  removed  from  the  wound 
should  not  be  permitted  to  remain  about  the  room.  If,  for 
reasons  of  economy,  they  are  to  be  used  again,  they  should 
be  disinfected  and  finally  washed,  dried,  ironed,  rolled,  and 
sterilized  by  steam.  If  not  to  be  used  again,  they  should  be 
burned. 

It  is  not  generally  advisable  to  employ  chemical  disin- 
fectants and  antiseptics  about  wounds  for  the  purpose  of 
prophylaxis,  for  the  reason  that  they  usually  defeat  the  very 
object  for  which  they  are  employed,  by  converting  the  tissues 
into  a  nidus  favorable  to  the  growth  of  micro-organisms.  By 
the  action  of  such  substances  the  vitality  of  the  tissues  is 
often  destroyed  through  the  induction  of  necrotic  changes, 
and  they  are  in  this  way  deprived  of  the  means  with  which 
nature  has  endowed  them  for  resisting  infection. 


140  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 


VENEREAL  DISEASES, 

(  GoJiofvhea  and  Syphilis. ) 

Gonorrhea. — A  specific  inflammation  of  the  mucous 
membrane  of  the  urethra  in  the  male,  and  of  the  urethra, 
cervix  uteri,  and  glands  of  Bartholini  in  the  female.  It  is 
caused  by  a  micrococcus  discovered  by  Neisser,  and  com- 
monly known  as  the  "  gonococcus  of  Neisser,"  or  as  micro- 
coccus gonorrJicece.  This  organism  is  recognized  microscop- 
ically in  gonorrheal  pus  by  its  tendency  to  occur  in  pairs 
(diplococci) ;  by  its  relation  to  the  pus-cells — /.  c,  by  being 
located  within  the  protoplasmic  bodies  of  these  cells  (Fig.  i6) ; 


Fig.  i6.— Pus  of  gonorrhea,  showing  presence  of  gonococci  in  the  bodies  of 
several  pus-cells. 

and  by  its  peculiar  staining  reactions — namely,  its  failure  to 
retain  the  stain  when  treated  by  the  process  of  Gram,  while 
it  stains  readily  when  exposed  to  any  of  the  ordinary  basic 
anilin  dyes.  Its  failure  to  stain  by  the  Gram  method  is  one 
of  the  most  important  differential  reactions.  It  can  be  culti- 
vated, but  not  on  the  ordinary  nutrient  media  employed  in 
bacteriological  work.  (For  the  methods  of  cultivation  see 
recent  works  on  Bacteriology.) 

When  kept  at  body-temperature  artificial  cultures  of  this 


VENEREAL   DISEASES.  14I 

organism  have  been  observed  to  retain  their  vitahty  for  as 
long  as  a  month  ;  whereas  at  ordinary  room-temperature  they 
die  in  about  forty-eight  hours. 

It  is  destroyed  in  a  {<t\\  hours  by  drying.  It  is  non-patho- 
genic for  animals.  Both  gonorrhea  and  conjunctivitis  have 
been  produced  in  man  through  the  use  of  pure  cultures  of 
this  organism. 

Syphilis. — A  chronic  infectious  disease  characterized  by 
manifold  pathological  lesions,  of  which  the  chancre,  the 
mucous  patch,  and  the  gumma  are  the  most  destructive. 

Though  numerous  claims  have  been  made  for  the  dis- 
covery of  micro-organisms  that  stand  in  causal  relation  to 
the  disease,  its  etiology  is  still  unknown.  Of  these  claims, 
the  one  that  has  received  the  greatest  consideration  is  that  of 
Lustgarten.  He  described  as  the  cause  of  syphilis  an  organ- 
ism that  he  had  discovered  microscopically  in  the  primary 
sore,  in  the  secretions  of  syphilitic  ulcers,  and  in  other  syph- 
ilitic lesions.  This  organism  is  a  bacillus  possessing  many 
of  the  characteristics  of  bacillus  tuber  ado  sis,  and  evidently 
belonging  to  the  group  of  which  the  tubercle  bacillus  is  the 
most  important  member.  In  many  respects  it  is  identical 
with  a  bacillus,  morphologically  like  it,  that  is  commonly 
present  in  the  smegma  from  about  the  prepuce  and  labia.  It 
likewise  has  peculiarities  that  are  common  to  the  bacillus  of 
leprosy.  The  four  organisms  mentioned — viz.,  bacillus 
tuberculosis,  bacilhis  smegniatis,  bacillus  lepr<^,  and  bacillus 
syphilidis — are  distinguished  microscopically  from  one  another 
by  particular  processes.  (For  the  differential  method  see 
works  on  Bacteriology.) 

The  so-called  "  syphilis  bacillus  "  has  not  been  isolated  in 
culture,  nor  has  the  disease  been  reproduced  in  animals  by 
inoculation  with  secretions  from  syphilitic  ulcers,  or  with  bits 
of  syphilitic  tissue.  Lustgarten's  claim  rests  simply  upon  the 
finding  of  this  organism  in  syphilitic  lesions  by  microscopical 
methods.  Though  certain  other  observers  have  confirmed 
Lustgarten's  observations,  a  great  many  more  have  failed  to 
detect  the  organism  after  careful  search  through  the  most 
promising  materials.     There  is  therefore  considerable  room 


142  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

for  doubt  as  to  the  causal  relation  of  this  organism  to 
syphilis. 

Dissemination,  Modes  of  Infection,  etc. — In  the  vast 
majority  of  cases,  both  gonorrhea  and  syphilis  are  dissemi- 
nated through  actual  contact  with  the  secretions  of  diseased 
tissues  during  sexual  intercourse.  The  introduction  of  gon- 
orrheal pus  into  the  eye  results  in  a  serious  variety  of  puru- 
lent ophthalmia — viz.,  gonorrheal  conjunctivitis,  and  a  condi- 
tion (ophthalmia  neonatorum)  not  rarely  seen  in  the  new-born 
of  women  affected  with  gonorrhea,  may,  and  often  does, 
result  in  loss  of  sight  unless  promptly  and  judiciously 
brought  under  medical  treatment.  It  is  not  unlikely  that 
gonorrheal  ophthalmia  may  be  contracted  through  the  use 
of  towels  that  have  been  employed  by  persons  suffering  from 
gonorrheal  urethritis.  Syphilis  may  be  disseminated,  in  addi- 
tion to  the  usual  way,  through  kissing  and  through  the  use 
of  drinking  and  eating  utensils  that  have  been  used  by  per- 
sons suffering  from  syphilitic  lesions  of  the  buccal  mucous 
membrane.  It  may  be  contracted  by  the  wet-nurse  who 
suckles  a  syphilitic  child,  or  may  be  given  in  a  variety  of 
ways  by  a  syphilitic  nurse  to  a  healthy  baby  that  is  placed  in 
her  care. 

It  is  occasionally  contracted  by  physicians  in  the  perform- 
ance of  professional  duties,  through  the  infection  of  wounds 
in  the  hands  with  syphilitic  secretions. 

Attention  of  dentists  has  been  called  to  the  possibility  of 
their  disseminating  this  disease  from  persons  suffering  from 
lesions  of  the  oral  cavity,  unless  proper  precautions  be  taken. 
Bulkley  has  called  attention  not  only  to  a  case  of  syphilitic 
infection  transmitted  in  this  way,  but  also  to  one  in  which  the 
operator  himself  contracted  the  disease  through  infection  of  a 
wound  of  the  finger. 

In  short,  abraded  surfaces  when  brought  in  immediate  con- 
tact with  the  blood  or  secretions  from  primaiy  or  secondary 
lesions,  in  any  way  whatsovcr,  are  practically  certain  to  be- 
come infected.     Syphilis  may  be  transmitted  by  heredity. 

It  may  be  inherited  from  the  father,  the  mother  being 
healthy,   or  frmii   a   s\-phi!itic   mother.     A   most  interesting 


VENEREAL   DISEASES.  1 43 

phenomenon  is  that  embodied  in  Colles's  Law — viz.,  "  a  child 
born  of  a  mother  who  is  without  obvious  venereal  symp- 
toms, and  which,  without  being  exposed  to  any  infection 
subsequent  to  its  birth,  shows  this  disease  when  a  few  weeks 
old — this  child  will  infect  the  most  healthy  nurse,  whether 
she  suckle  it  or  merely  handle  and  dress  it ;  and  yet  the  child 
is  never  known  to  infect  its  own  mother,  even  though  she 
suckle  it  while  it  has  venereal  ulcers  of  the  lips  and  tongue." 
Hereditary  transmission  of  the  disease  is  most  apt  to  occur 
when  conception  takes  place  during  the  primary  stages  of 
the  disease.  Syphilis  in  a  parent  may  have  apparently  dis- 
appeared under  treatment,  and  yet  offspring  born  subse- 
quently may  manifest  inherited  evidences  of  the  disease. 

The  mortality  among  children  born  of  syphilitic  parents 
is  high.  Kryhus  '  states  that  in  the  Hospital  St.  Louis  24 
per  cent,  of  syphilitic  women  abort,  and  in  the  Hospital  Lour- 
cine  38  per  cent,  are  liable  to  this  accident.  Of  children  born 
of  syphilitic  fathers  48  per  cent,  die,  while  78  per  cent,  suc- 
cumb when  both  parents  are  affected  with  the  disease.  The 
infantile  mortality  decreases  with  increase  of  chronicity  of  the 
disease  in  the  parents.  Fournier  states  that  in  many  hos- 
pitals of  Paris  the  mortality  among  infants  born  of  syphilitic 
parents  reaches  84  to  86  per  cent. 

Prophylaxis. — That  the  vast  majority  of  venereal  dis- 
eases originate  through  impure  and  irregular  sexual  inter- 
course is  a  statement  over  which  there  can  be  little  contro- 
versy. 

It  is  not  my  purpose  to  discuss  here  the  moral  aspect  of 
prostitution ;  neither  are  we  to  be  understood  as  endorsing 
the  evil  by  stating  that  it  has  existed  as  long  as  peoples  have 
existed,  and  from  the  present  outlook  there  is  little  likelihood 
of  its  disappearance.  In  view  of  the  moral,  social,  and 
physical  ravages  that  follow  in  the  wake  of  venereal  diseases, 
it  behooves  us  to  employ  every  measure  that  is  within  our 
power  to  combat  these  maladies  and  lessen  their  frequency. 

The  trustworthy  personal  measure  against  venereal  dis- 
eases, as  contracted  in  the  usual  way,  is  celibacy,  and  it  is 

^  These  de  Paris,  1890. 


144  IIYGIEXE    OF   TRANSMISSIBLE   DISEASES. 

the  dut)'  of  the  physician  to  teach  this  doctrine,  even  though 
he  may  feel  that  its  adoption  is  in  many  cases  a  matter  of 
grave  doubt ;  not  because  continence  is  an  impossible  condi- 
tion, but  rather  because  for  many  men  it  involves  a  kind  of 
personal  discipline  that  they  are  loath  to  undertake.  Sexual 
desire  is  often  one  of  the  manifestations  of  stored-up  energy 
resulting  from  idleness  and  intemperance.  The  greatest  aids 
to  a  continent  life  are  hard  work,  athletic  exercise,  temper- 
ance in  food  and  drink,  and  the  avoidance  of  temptation.  For 
many  men  celibacy  for  an  indefinite  period  is  apparently  im- 
possible. Such  men  should  be  advised  to  marry,  even  though 
personal  sacrifices  in  certain  directions  must  be  made  by  so 
doing. 

That  a  large  proportion  of  unmarried  men  prefer  to  satisfy 
their  sexual  cravings  by  recourse  to  the  usual  method,  rather 
than  endeavor  to  repress  them,  is  a  fact  that  cannot  be  ig- 
nored ;  and  while  the  recommendation  of  personal  preventive 
measures  to  meet  the  exigencies  of  such  cases  may  appear 
as  favoring  immorality,  it  must  be  remembered  th'at  the  task 
now  in  hand  is  the  prevention  of  disease,  and  not  the  en- 
forcement of  moral  precepts.  Under  such  circumstances 
something  may  be  done  to  prevent  contagion  by  scrupulous 
cleanliness  and  careful  local  disinfection  after  intercourse  ; 
but  it  must  also  be  borne  in  mind  that  none  of  these  meas- 
ures affords  certain  protection.  In  a  number  of  European 
towns,  especially  in  France,  the  use  of  disinfectant  lotions  by 
prostitutes  is  rigorously  enforced,  with  the  result  of  consider- 
ably reducing  the  frequency  of  venereal  diseases. 

The  prophylactic  measures  of  greatest  efficiency  are  ad- 
ministrative. The  question  of  prostitution  is  a  matter  for  the 
State  to  consider  in  its  relation  to  the  public  health.  A  per- 
son afflicted  with  a  venereal  disease  is  a  menace  to  the  public 
health,  and  is  just  as  much  a  subject  for  State  control  as 
would  be  a  case  of  small-pox  or  of  any  other  communicable 
malady.  In  the  majority  of  European  countries  laws  have 
been  enacted  that  aim  to  limit  the  dissemination  of  these  dis- 
eases, and  in  the  main  their  effect  has  been  most  salutary. 
These  laws  provide  for  the  registration,  usually  at  a  bureau 


VENEREAL    DISEASES.  1 45 

of  the  department  of  police,  of  all  women  who  subsist  by 
prostitution  ;  for  (in  some  places)  their  segregation  in  brothels 
or  in  particular  parts  of  the  town  ;  and  for  their  regular  and 
frequent  examination  by  competent  physicians  who  are  de- 
tailed for  the  purpose.  In  addition,  the  law  should  provide 
for  the  treatment,  without  cost  to  the  individual,  of  all  vene- 
real cases  in  hospitals  properly  equipped  for  the  purpose. 

In  France,  Germany,  Denmark,  and  England  (prior  to  the 
repeal  of  the  Contagious  Diseases  Act  in  the  last-named 
country  in  1884)  the  relative  frequency  of  venereal  diseases 
has  markedly  diminished  as  the  methods  of  municipal  con- 
trol of  prostitution  have  gained  in  efficiency.  Nevertheless, 
the  enactment  of  these  laws,  operating  manifestly  for  the 
public  good,  has  given  rise  to  no  end  of  controversy,  and 
has  in  some  places  (particularly  in  England)  met  with  vig- 
orous opposition  from  those  who,  fully  aware  of  the  existence 
of  an  evil  that  cannot  be  eradicated,  consider  it  as  immoral 
to  sanction  the  only  feasible  plan  for  diminishing  its  baneful 
influence  upon  the  physical  well-being  of  the  community. 
Where  such  laws  have  been  enacted  and  enforced,  their 
result,  more  particularly  upon  the  number  of  syphilitic 
infections,  has  been  most  marked.  This  was  conspicuously 
noticeable  at  those  army-posts  in  England  that  were  under 
the  Contagious   Diseases  Act  prior  to  its  repeal  in  1884. 

An  element  that  disturbs  the  still  more  successful  opera- 
tion of  the  law  is  everywhere  recognized  in  clandestine  pros- 
titution that  always  obtains  among  women  of  a  certain  class. 
It  is  usually  impossible  to  bring  all  such  women  under  the 
operation  of  the  law,  though  the  experience  of  a  number  of 
places  shows  that  many  of  this  class,  realizing  the  material 
advantages  to  be  derived  from  skilful  medical  control  and 
attention,  have  voluntarily  presented  themselves  for  registra- 
tion. Moreover,  there  is  reason  to  believe  that  the  frequent 
and  dignified  medical  inspection  has  in  general  an  educational 
influence  upon  public  women.  They  realize  that  they  are 
under  restraint ;  they  take  better  care  of  themselves,  for  they 
are  sent  to  hospital  if  found  diseased,  and  their  trade  is  neces- 
sarily thereby  interrupted ;  and,  while  perhaps  no  better  off 
10 


146  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

moral  1)-,  the}'  are  less  frequently  guilty  of  breaches  of  public 
decency.  At  least,  the  experience  of  a  number  of  places  has 
led  to  this  opinion. 

The  experience  of  those  communities  in  which  laws  for  the 
regulation  of  prostitution  have  been  enacted  has  brought  out 
two  important  facts — viz.,  that  the  unlicensed,  uncontrolled 
public  woman  is  the  great  source  of  dissemination  of  venereal 
infection,  and  that  by  the  enforcement  of  carefully  constructed 
municipal  laws  the  amount  of  venereal  disease  may  be  mate- 
rially diminished. 

The  results  of  medical  examination  of  prostitutes  in  those 
places  in  which  registration  is  in  force  clearly  illustrate  the 
dangerous  nature  of  those  women  who  are  not  regularly  within 
the  operation  of  the  law ;  for  instance,  Commengue  states 
that  of  913,291  registered  medical  examinations  of  prostitutes 
in  Paris  between  the  years  1878  and  1887  syphilis  was  found 
to  be  present  per  looo  examinations  3.12  times  in  registered 
prostitutes  living  privately,  2.70  times  in  registered  prostitutes 
in  brothels,  23.96  times  in  work-girls,  and  166  times  in  pros- 
titutes not  under  control.  Essentially  the  same  proportions 
held  for  gonorrhea,  except  in  the  case  of  work-girls,  when  it 
was  found  to  be  144.6  for  lOOO  of  all  examinations.  In 
Lyons  Giraud  found  that  from  1.34  per  cent,  to  1.61  per  cent, 
of  registered  women  were  diseased,  while  33.11  per  cent,  of 
those  not  under  control  were  suffering  from  venereal  troubles. 
In  Denmark  (1889)  venereal  diseases  were  present  in  4.27 
per  cent,  of  registered  women  under  control ;  in  1 7.64  per 
cent,  of  non-registered  women  who  voluntarily  presented 
themselves  for  examination  ;  and  in  39.49  per  cent,  of  clan- 
destine prostitutes  not  under  control  and  not  regularly 
examined.  Illustrative  of  the  influence  of  these  laws: 
when  the  registration  laws  were  passed  in  Rostock  in  1881, 
the  number  of  cases  of  syphilis  that  applied  for  medical 
advice  in  that  year  was  240;  during  the  six  succeeding 
years,  under  the  influence  of  the  law,  the  number  of  cases 
was  269  in  1882,  164  in  1883,  1 13  in  1884,  92  in  1885,  92  in 
1886,  and  70  in  1887.^     While  the  Contagious  Di.seases  Act 

*  Hygienische  Topographic  von  Rostock,  1889. 


VENEREAL    DISEASES.  I47 

was  in  operation  in  England  (1864- 1883),  the  amount  of 
syphilis  was  markedly  diminished.  Since  the  repeal  of  the 
Act  in  1884  venereal  diseases  in  the  army  have  reverted  in 
extent  and  severity  to  what  they  were  before  the  Act  was 
passed.  According  to  Balfour  the  admissions  to  army  hos- 
pitals in  1864  (the  year  before  the  enactment  of  the  law)  for 
primary  chancre  were  108.6  per  1000.  In  1872  the  admis- 
sions at  the  uncontrolled  stations  were  still  higher — viz.,  123.2 
per  1000 — while  in  the  same  year  the  admissions  at  the  army 
stations  that  were  nnder  the  control  of  the  Act  were  only 
53.3  per   1000. 

Parke  states  that  the  number  of  admissions  to  the  hospitals 
of  all  military  stations  under  the  Act  (comprising  a  total  of 
30,765  men)  from  1867-72  for  primary  venereal  sore  was 
62.8  per  1000,  while  the  admissions  from  these  same  stations 
just  after  the  repeal  of  the  Act  were  no  per  1000  in  1883 
and  138  per  1000  in  1884.  "  So  that  things  are  rapidly  fall- 
ing back  into  their  old  evil  conditions."  Such  statistics  as  the 
foregoing  require  no  comment.     They  tell  their  own  story. 

As  has  already  been  said,  to  many  it  may  appear  improper 
to  advocate  a  method  by  which  the  community  acknowledges 
and  openly  licenses  a  practice  that  is  plainly  a  breach  of 
public  morals.  But  the  evil  exists  ;  it  is  likely  to  exist ;  and 
nothing  is  gained — on  the  contrary  much  is  lost — by  calmly 
closing  the  eyes  to  it.  The  evils  of  prostitution  are  more 
far-reaching  and  are  a  greater  menace  to  the  public  health, 
morals,  and  happiness  than  a  superficial  examination  would 
indicate.  It  is  our  duty  as  physicians  and  as  citizens  to  cir- 
cumvent this  evil,  and  we  can  do  this  only  by  seriously  rec- 
ognizing it,  not  by  ignoring  it. 

As  Osier  aptly  puts  it :  "  If  the  offender  bore  the  cross 
alone,  I  would  say  forbear;  but  the  physician  behind  the 
scenes  knows  that  in  countless  instances  syphilis  has  wrought 
havoc  among  innocent  mothers  and  helpless  infants,  often 
entailing  lifelong  suffering.  It  is  for  them  he  advocates 
protective  measures." 


148  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

LEPROSY. 

Definition,  Cause,  etc. — A  chronic,  endemic,  infectious 
disease  caused  by  a  specinc  micro-organism,  bacillus  Icprce, 
which  possesses  certain  peculiarities  in  common  with  bacillus 
tuberculosis. 

The  disease  occurs  in  three  forms,  viz. : 

1.  The  tubercular  leprosy,  in  which  nodular  eruptions 
occur  on  the  skin  of  the  face,  limbs,  breasts,  scrotum  and 
penis,  and  also  on  the  mucous  membranes. 

2.  The  non-tuberculated  or  so-called  "  anesthetic  leprosy," 
in  which  the  peripheral  sensory  nerves  are  at  first  involved. 
This  is  followed  after  a  time  by  a  peculiar,  flat,  dry,  scaly 
eruption  on  the  back,  shoulders,  posterior  surfaces  of  the 
arms,  about  the  nails,  and  at  times  along  the  course  of  the 
nerves.  In  the  earliest  stages  the  affected  areas  are  hyper- 
esthetic  ;   during  the  eruptive  stage  they  become  anesthetic. 

3.  Mixed  tubercular  leprosy — /'.  c,  a  combination  of  the 
two  forms  just  mentioned.  This  is  the  least  common  mani- 
festation of  the  disease. 

The  non-tubercular  or  anesthetic  variety  is  that  most 
frequent  in  the  Tropics. 

Bacillus  IcprcF,  now  generally  believed  to  be  the  cause  of 
the  disease,  was  discovered  in  the  pathological  lesions  of 
leprosy  by  Hansen  and  by  Neisser  between  1879  and   1881. 

Morphologically,  it  is  so  like  bacillus  tuberculosis  as  to  be 
practically  identical  with  it,  though  some  authors  consider  it 
to  be  shorter,  a  distinction  that  alone  counts  for  but  little. 
It  is  said  to  be  differentiated  from  bacillus  tuberculosis  by 
special  staining  reactions.  Though  several  authors  (Bordoni- 
Ufreduzzi,  Ducrey,  and  Campana)  claim  to  have  cultivated 
this  organism,  it  is  doubtful  if  it  has  ever  been  grown  artifici- 
ally. In  fact,  such  a  number  of  efforts  to  culti\'ate  it  from 
skin-lesions  by  trustworthy'  investigators  ha\c  resulted  in 
failure,  that  the  general  impression  now  is  that  the  majority 
of  the  bacilli  seen  in  the  tissues  are  dead.  At  all  e\'ents,  one 
of  their  most  frequent  microscopical  peculiarities  is  a  con- 
spicuous degree  of  apparent  degeneration. 


LEPROSY. 


149 


On  microscopical  examination  with  low  magnifying  powers 
of  sections  of  leprous  tissue  stained  by  any  of  the  methods 
used  for  staining  tubercle  bacilli  in  tissues,  the  leprosy  bacil- 
lus is  detected  usually  in  enormous  numbers.  It  will  be 
seen  scattered  through  the  tissue  as  smaller  and  larger 
clumps  of  individual  bacilH  (Fig.  17).  On  examining  these 
clumps  under  a  high  magnifying  power,  they  will  usually  be 


Fig.  17. — Schematic  representation  of  section  through  a  lepra  nodule  :  left 
side  of  picture  gives  appearance  under  low  magnifying  power  ;  right  side,  the 
appearance  when  highly  magnified.  In  the  latter  the  large  lepra  cells  are 
diagrammatically  indicated. 

found  to  represent  single  granulation-cells  that  are  packed 
with  the  bacilli — the  so-called  "  lepra-cells  " — of  which  a 
large  part  of  the  new  growth  is  composed.  The  bacilli  are 
irregularly  stained,  often  irregular  in  outline,  beaded  and 
broken,  and,  as  said,  usually  present  the  appearance  of 
degeneration.  The  bacilli  are  also  present  in  the  secretions 
that  may  exude  or  be  squeezed  from  the  leprous  nodule  in 
situ.  They  have  been  found  in  the  circulating  blood,  but 
only  in  very  small  numbers.  Sticker  found  them  in  the  nasal 
discharges  from  128  out  of  153  cases  examined  by  him.  In 
only  23  of  these  153  cases  did  he  find  them  in  the  sputum. 
They  may  be  detected  microscopically  by  the  ordinary 
methods  used  for  the  detection  of  tubercle  bacilli  in  sputum 
or  in  pathological  secretions. 


150  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

The  disease  has  never  been  reproduced  in  animals  by 
inoculation  with  fresh  leprosy  tissues  or  secretions.  The 
efforts  to  reproduce  the  disease  in  man  by  inoculation  with 
fresh  leprosy  tissue  have  been  hardly  more  successful. 

During  the  past  fifty  years  an  astonishingly  large  number 
of  individuals  have  permitted  themselves  to  be  inoculated 
with  the  pathological  products  of  the  disease  without  leprosy 
resulting  in  but  a  single  instance,  and  there  is  doubt  as  to 
this  individual's  freedom  from  the  disease  at  the  time  of  his 
inoculation.  In  his  resume  of  the  literature  on  this  subject 
Walters  ^  cites  at  least  73  authenticated  inoculations  of 
human  subjects.  Some  of  these  were  in  good  health,  others 
suffering  from  other  maladies,  and  others  already  leprous, 
the  inoculations  in  the  last  instance  having  been  made  on 
non-affected  parts  of  the  body.  In  not  a  single  case  did 
leprosy  result. 

The  much-quoted  case  of  Arnig,  in  which  leprosy  appeared 
in  a  man  sixteen  months  after  he  had  inoculated  him,  loses 
much  of  its  value  as  a  demonstration  that  leprosy  may  be 
induced  in  this  way,  by  a  closer  study  of  the  conditions 
under  which  the  test  was  made.  The  subject,  a  Hawaiian 
convict,  had  a  family  history  of  leprosy,  several  relatives 
having  died  of  the  disease.  Arnig  himself  does  not  consider 
the  results  of  his  inoculation  as  a  demonstration  free  from 
objection. 

Geographical  Distribution,  Race,  etc. — Leprosy  is 
endemic  in  Japan  ;  on  the  coast  of  China ;  throughout  India 
and  the  Indian  archipelago  ;  in  isolated  districts  along  the 
coast  of  Africa,  especially  that  of  western,  northern,  and 
northeastern  Africa,  though  it  is  also  found  in  Cape  Colony ; 
along  the  southern  shores  of  the  Black  Sea ;  throughout  the 
Greek  archipelago  ;  along  the  western  coast  of  Norway  ;  in 
Iceland ;  in  certain  parts  of  New  Brunswick  and  Nova 
Scotia ;  in  Mexico ;  among  the  Chinese  in  southern  Cali- 
fornia ;  in  Louisiana  ;  in  the  West  Indies,  especially  Cuba ; 
in  Brazil,  and  in  the  Argentine  Republic  and  the  neighboring 
districts. 

1  Ccnti-nlhL  fitr  Bdklcriologic  iDid  Parasilciikundc,  1893,  W\.  xiii.,  S.  469. 


LEPROSY.  151 

The  character  of  the  disease  varies  somewhat  according  to 
location — viz.,  in  the  temperate  and  colder  climates  tubercu- 
lar leprosy  is  the  predominating  form,  while  in  the  tropics  the 
anesthetic  variety  is  more  common.  While  occurring  at  all 
ages  and  among  all  classes  of  people,  it  is  seen  oftenest  among 
the  poor  and  destitute.  According  to  Hirsch,  the  disease  is 
usually  encountered  in  countries  of  heterogeneous  popula- 
tions, negroes  and  those  of  mixed  blood  being  much  more 
frequently  affected  than  are  Europeans.  In  certain  localities 
in  the  Orient,  where  the  disease  is  endemic,  the  Arabs  and 
pure-blooded  East  Indians  have  shown  a  peculiar  insuscepti- 
bility to  it. 

In  the  colder  climates,  as  in  Norway  and  Iceland,  the 
purity  of  the  race  has  no  apparent  influence  upon  the  fre- 
quency of  the  disease. 

Hirsch  calls  attention  to  the  peculiar  differences  that  are 
seen  in  the  reaction  of  the  Jewish  race  to  leprosy  in  different 
parts  of  the  world.  In  Jamaica,  St.  Vincent,  and  Surinam, 
the  frequency  of  the  disease  among  the  Jews  is  second  only 
to  that  seen  in  the  negroes ;  while  in  Syria,  Damascus,  Jeru- 
salem, Bombay,  and  other  places  they  are  but  rarely  affected. 

Dissemination,  Modes  of  Infection,  etc. — While  no 
doubt  exists  as  to  the  infectious  nature  of  leprosy,  there  is 
little  agreement  of  opinion  as  to  its  mode  of  dissemination. 

The  disease  shows  no  special  tendency  to  spread  beyond 
the  boundaries  within  which  it  is  endemic,  and  healthy  indi- 
viduals are  known  to  have  spent  long  years  of  intimate  asso- 
ciation with  lepers  without  contracting  the  disease. 

Many  of  those  who  have  investigated  the  subject  are  of 
the  opinion  that  leprosy  is  rarely,  if  ever,  transmitted  from 
the  diseased  to  the  headthy  person  by  direct  contact,  while 
other  observers  claim  this  to  be  its  most  frequent  mode  of 
transmission. 

The  mass  of  evidence  compiled  by  Hirsch  in  opposition  to 
its  transmission  by  contact  is  very  strongly  in  favor  of  the 
view  that  this  must  be  a  very  unusual  mode  of  dissemination, 
if  it  occurs  at  all. 

Some  believe  that,  as  in  the  case  of  syphilis,  one  may  often 


152  HYGrENE    OE   TRAXSMISSIBLE   DISEASES. 

be  in  intimate  association  with  the  diseased  persons  for  long 
periods  without  becoming  infected,  but  finally  in  some  inex- 
plicable way  the  disease  is  contracted.  It  has  been  suggested 
that,  like  syphilis,  there  may  be  periods  when  leprosy  is  emi- 
nently communicable,  while  in  other  stages  this  peculiarity 
is  diminished  or  lost.  There  is  a  pretty  general  agreement  of 
opinion  that  the  anesthetic  is  much  less  readily  communica- 
ble than  is  the  tubercular  variety  of  leprosy. 

The  disease  starts  with  no  primary  sore  or  point  of  in- 
vasion that  can  be  accurately  determined.  Its  usual  mode  of 
onset  as  multiple  foci  leads  to  the  opinion  that  through  some 
unknown  channel  a  number  of  areas  in  the  skin  must  have 
served  simultaneously  as  points  of  deposit  for  the  morbific 
causative  agent.  Whether  such  infection  is  from  without,  or 
starts  from  some  primary  focus,  the  nasal  mucous  membrane 
for  instance,  as  is  believed  by  Sticker,  cannot  be  positively 
affirmed.  Nor  can  it  be  definitely  stated  that  leprosy  is  con- 
tracted by  way  of  the  lungs  or  alimentar}-'  tract,  though  some 
observers  believe  this  possible.  The  negative  results  that 
have  followed  inoculations  in  human  beings  lead  to  the  opin- 
ion that  it  cannot  be  transmitted  by  inoculation  ;  though 
Hansen  is  of  the  opinion  that  it  is  often  contracted  through 
abrasions  of  the  skin,  through  the  wearing  of  clothing  that 
has  been  worn  by  lepers,  and  through  the  intimate  association 
between  the  sick  and  the  well,  that  is  often  observed  among 
the  ignorant  and  destitute. 

The  increase  of  leprosy  in  late  years  in  the  Sandwich 
Islands  is  held  by  some  to  be  the  result  of  direct  transmis- 
.sion,  occurring  very  often  through  sexual  intercourse. 

At  the  first  Leprosy  Congress  held  in  Berlin  in  Octoh)cr, 
1897,  various  speakers  on  the  subject  expressed  the  belief 
that  the  disease  could  be  contracted  by  way  of  the  mucous 
membrane  of  the  nostrils,  and  the  skin  about  the  face ; 
through  wounds  of  the  skin  ;  that  it  could  be  disseminated 
from  the  infected  individuals  through  saliva  and  mucus  from 
the  mouth  and  nose  ;  that  it  could  be  transmitted  by  the 
handling  of  infected  clothing ;  that  it  could  be  carried  by  in- 


LEPROSY. 


153 


sects  ;  and  that  it  could  be  conveyed  through  the  milk  of  the 
nursing  mother  to  her  child. 

The  perpetuation  of  the  disease  is  believed,  by  those  who 
oppose  the  idea  of  its  transmission  by  direct  contact,  to  be 
due  to  heredity.  On  this  point,  too,  there  is  divergence  of 
opinion,  though  no  one  denies  that  inheritance  is  one  of  the 
zvays  through  which  it  is  disseminated.  Hirsch,  as  a  result 
of  his  investigations,  believes  inheritance  to  be  the  only  dem- 
onstrated mode  of  transmission  for  leprosy,  and  in  this  opin- 
ion a  number,  though  by  no  means  all,  of  the  most  compe- 
tent authorities  concur. 

The  opinion  has  been  advanced  that  certain  articles  of  food, 
notably  fresh,  salted,  and  rotten  fish  (Jonathan  Hutchinson), 
pork,  and  decomposed  rice,  are  especially  predisposing  to  the 
disease.  Investigation  readily  demonstrates  the  fallacy  of 
this  view.  In  several  of  the  areas  of  distribution  fish,  in  one 
form  or  another,  is  the  staple  article  of  food  for  the  entire 
population,  and  yet  leprosy  does  not  spread  beyond  the  con- 
fines of  the  isolated  districts  in  which  it  is  endemic. 

It  has  also  been  erroneously  claimed  that  certain  atmos- 
pheric conditions  favor  the  existence  of  the  disease.  No 
connection  can  be  established  between  leprosy  and  climate  or 
season.  While  frequent  along  the  coasts,  its  general  area  of 
distribution  disproves  a  necessary  dependence  upon  littoral 
'conditions. 

Prophylaxis. — It  is  manifest  that  without  a  clearer  un- 
derstanding of  the  mode  of  dissemination  and  the  portals  of 
infection  of  a  disease,  any  measures  that  may  be  recom- 
mended for  the  prevention  of  its  spread  are  of  necessity  un- 
satisfactory and  incomplete.  From  what  has  been  said  as  to 
the  disagreement  of  opinion  concerning  the  communicability 
of  leprosy,  we  are  prepared  for  irregularities  in  the  methods 
employed  in  its  management.  In  some  places  no  attention 
is  paid  to  the  disease  at  all ;  the  lepers  mingle  with  the  gen- 
eral population  and  enjoy  the  same  liberty  as  do  the  unaf- 
fected citizens.  In  other  places  efforts  are  employed  to  sepa- 
rate them  from  the  people  at  large  by  systems  of  segrega- 
tion, as  in  colonies,  or  upon  farms,  or  in  asylums.     The  Eng- 


154  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

lish  Leprosy  Commission  considers  compulsory  segregation 
as  unnecessary,  while  the  unanimous  opinion  of  the  First  In- 
ternational Scientific  Leprosy  Conference  (Berlin,  October, 
1897)  was  :  "  That  segregation  is  the  best  means  of  prevent- 
ing the  spread  of  leprosy,  and  that  for  all  countries  in  which 
the  disease  exists  (endemically)  it  is  further  recommended 
that  compulsory  notification,  medical  supervision,  and  isola- 
tion of  individual  cases  be  enforced." 

Notwithstanding  the  fact  that  obligatory  segregation  or 
isolation  has  never  been  practised  in  Norway,  the  disease  has, 
through  intelligent  management,  been  markedly  diminished. 
His  observations  in  Norway  lead  Hansen  to  the  opinion  that 
the  spread  of  leprosy  may  be  very  much  checked  by  scrupu- 
lous cleanliness,  both  personal  and  domestic,  on  the  part  of 
the  patient ;  by  the  observation  of  this  the  patient  can  in 
large  measure  isolate  himself  in  his  own  home. 

Where  destitute  lepers  are  present  in  number,  it  becomes 
the  duty  of  the  State  to  provide  for  their  care  in  properly 
equipped  isolation  hospitals  or  asylums,  or  in  carefully  regu- 
lated colonies.  According  to  the  demands  of  the  case,  isola- 
tion under  these  circumstances  may  be  partial  or  absolute. 

At  the  Berlin  Conference  attention  was  also  attracted  to 
the  importance  of  regarding  the  diseased  tissue  as  a  source 
of  infection  to  others,  and  with  this  in  view  it  was  recom- 
mended that  the  dissemination  of  infective  materials  from 
these  tissues  be  prevented  by  the  use  of  antiseptic  ointments, 
bandages,  and  dressings. 

If  in  countries  where  the  disease  is  endemic,  the  public  be 
educated  to  the  full  appreciation  of  its  dangers,  as  Hansen 
has  taken  great  pains  to  do  in  Norway,  isolation  and  segre- 
gation may  be  forced  upon  the  lepers  without  legal  aid^that 
is  to  say,  by  refusing  to  employ  them,  by  refusing  to  assist 
them,  by  denying  their  admission  to  public  buildings,  convey- 
ances, etc. — they  are  finally  driven  for  self-preservation  to 
separate  themselves  from  the  general    public. 

Lepers  should,  if  possible,  be  induced  to  live  apart  from 
the  healthy  population,  preferably  colonized  in  some  agricul- 
tural district.     Such  colonics  should  be  provided  with  hos- 


TETANUS.  155 

pitals  or  lazarettos  properly  equipped  for  the  management 
and  study  of  such  cases  as  require  medical  aid.  Where  seg- 
regation of  lepers  has  been  insisted  upon,  the  number  of  cases 
in  the  locality  has  almost  uniformly  decreased. 

As  in  the  vast  majority  of  cases  the  disease  is  apparently 
transmitted  by  heredity,  the  marriage  of  lepers  should  always 
be  discouraged,  and,  if  possible,  be  prevented. 

They  should  be  prohibited  from  following  such  occupa- 
tions as  that  of  barber,  laundryman,  provisioner,  etc.,  that 
bring  them  in  more  or  less  immediate  contact  with  healthy 
persons. 


TETANUS. 

{^Lock-jaiv.^ 

Definition,  Cause,  etc. — An  acute  infectious  disease 
.caused  by  a  specific  micro-organism — bacillus  tetani — and 
characterized  by  frequent  and  long-continued  spasm  of  the 
voluntary  muscles. 

The  causative  agent — bacillus  tetani — was  discovered  by 
Nicolaier  in  1 884,  through  the  introduction  of  garden  earth 
beneath  the  skin  of  mice.  He  demonstrated  that  the  pus  or 
other  exudate  found  at  the  site  of  operation  in  the  tetanic 
mice  was  capable  of  inducing  the  disease  in  other  animals 
into  which  it  might  be  introduced.  The  bacillus  of  tetanus 
was  not  isolated  in  pure  culture  until  later  (1889),  when 
Kitasato  separated  it  by  special  anaerobic  methods  from  the 
other  forms  with  which  it  is  usually  associated,  and  proved 
its  causal  relation  to  the  disease,  by  the  inoculation  of  sus- 
ceptible animals  with  the  pure  cultures. 

The  bacillus  of  tetanus  has  been  detected  in  the  soil  of 
many  localities.  It  is  pretty  generally  distributed  in  the 
upper  layers  of  the  earth,  though  in  some  places  it  is  much 
more  numerous  than  in  others.  It  can  usually  be  demon- 
strated in  the  soil  of  gardens  that  are  fertilized  with  animal 
manure.     These  facts  explain  the  occasional  onset  of  tetanus 


156  HYGIENE    OE  TRANSMISSIBLE  DISEASES. 

after  wounds  into  which  earth  has  gained  access,  such  for 
instance  as  punctured  or  lacerated  wounds  of  the  feet  and 
hands  by  old  rusty  nails,  wooden  splinters  ;  crushed  wounds 
from  the  wheels  of  wagons,  carts,  etc. 

It  is  a  motile,  spore-forming,  anaerobic  bacillus  that  pos- 
sesses the  morphological  peculiarity,  when  in  the  spore-stage, 
the  only  condition  by  which  it  is  recognizable  microscopically, 
of  presenting  the  appearance  of  a  small  pin — /.  c,  the  oval, 
glistening,  unstained  spore  occupies  one  end  of  the  rod,  and 
serves  as  the  head,  while  the  slender  stained  body  of  the 
bacillus  forms  the  rest  of  the  pin-shaped  structure  (Fig.  18). 


Fig.  18. — Bacillus  tetani  from  artificial  culture. 

The  spores  of  bacillus  tetani  are  very  tenacious  of  life. 
They  are  not  destroyed  by  drying,  even  by  absolute  drying 
in  the  dessicator,  for  months.  They  are  killed  in  five  min- 
utes by  steam  at  100°  C,  but  they  resist  moist  heat  at  80° 
C.  for  one  hour.  They  are  not  destroyed  by  immersion  in  5 
per  cent,  carbolic  acid  for  ten  hours,  though  they  are  killed 
in  fifteen  hours  by  this  treatment. 

The  vegetative  form  of  the  organism  as  studied  in  pure 
culture  is  found  to  be  by  no  means  so  resistant  to  detrimental 
agencies  as  are  the  spores. 

As  it  is  an  obligate  anaerobe  (not  growing  in  the  presence 


TETANUS.  157 

of  free  oxygen),  it  requires  special  methods  for  its  isolation 
and  cultivation.     (See  works  on  Bacteriology.) 

After  the  subcutaneous  inoculation  of  mice,  rabbits,  and 
guinea-pigs  with  pure  cultures,  with  particles  of  earth,  with 
secretions  from  a  wound,  or  with  bits  of  tissue  containing 
this  organism,  typical  tetanus  supervenes  in  from  twenty-four 
to  thirty-six  hours,  and  usually  ends  fatally  in  from  two  to 
three  days.  As  a  rule,  the  spasms  begin  in  the  muscles 
nearest  the  site  of  inoculation.  In  animals  suffering  from 
experimentally  induced  tetanus  the  slightest  tap  on  the  cage 
or  the  least  disturbance  of  the  body  usually  suffices  to  bring 
on  the  characteristic  muscular  contractions.  At  autopsy  one 
may  find  either  an  area  of  suppuration  or  very  slight,  often 
hardly  distinguishable,  inflammatory  reaction  at  the  point  of 
operation.  The  suppuration  is  not  the  result  of  pathogenic 
activities  of  the  tetanus  bacilli,  but  rather  of  other,  pyogenic 
organisms,  that  the  earth  contained.  In  many  cases  the 
bacilli  may  be  detected  microscopically  and  isolated  by  cul- 
ture methods  from  the  tissues  at  the  site  of  inoculation,  but 
almost  as  often  they  are  missed. 

From  the  experimental  standpoint,  this  disease  is  of  much 
historic  interest,  since  it  was  while  investigating  tetanus  that 
Behring  and  Kitasato  made  the  observation  from  which  have 
been  elaborated  the  principles  underlying  the  employment  of 
the  serum  of  artificially  immunized  animals  for  the  cure  of 
disease. 

Geographical  Distribution,  Season,  Race.— In  both 
the  eastern  and  western  hemispheres  tetanus  is  much  more 
frequent  in  tropical  than  in  the  temperate  and  colder  climates  ; 
though  it  often  occurs  in  subtropical  localities,  as,  for  instance, 
in  the  southern  part  of  the  United  States,  where,  according 
to  all  accounts,  it  is  at  times  a  very  formidable  disease. 
Among  the  inhabitants  of  certain  of  the  Antilles  islands,  in 
Guiana,  Brazil,  and  Peru,  tetanus  now  and  again  occurs  with 
such  violence  as  almost  to  assume  an  epidemic  character. 

The  race  that  conspicuously  suffers  from  tetanus  is  the 
negro.  Whether  this  is  due  to  a  particular  vulnerability  of  the 
black  man  to  this  variety  of  infection  or  not  it  is  difficult  to 


158  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

say ;  but  certainly  his  preference  for  hot  climates,  his  social 
condition,  his  careless  personal  habits,  his  insufficient  cloth- 
ing, and  his  constant  exposure  to  the  character  of  injuries 
that  are  known  to  be  most  often  followed  by  tetanus,  are  im- 
portant factors  in  favoring  the  frequent  occurrence  of  the  dis- 
ease among  this  people.  The  disease  is  more  common  in 
spring  and  summer  than  at  other  seasons  of  the  year.  Its 
onset,  according  to  many  writers,  seems  to  be  especially  fav- 
ored by  sudden  and  extreme  fluctuations  in  the  weather,  as 
by  cold  nights  following  upon  hot  days,  by  the  sudden  occur- 
rence of  cold  rains  after  a  hot  spell,  and  by  cold,  moist  winds 
during  the  summer  months. 

Indeed,  practically  all  writers  on  this  disease,  prior  to  the 
discovery  of  its  bacterial  origin,  regarded  atmospheric  influ- 
ences as  the  most  important  etiological  factor.  Nowadays 
'little  weight  is  given  to  this  supposed  predisposing  influence 
of  meteorological  and  climatic  conditions.  Special  telluric 
conditions  do  not  appear  essential  to  the  existence  of  the  spe- 
cific virus. 

The  majority  of  domestic  animals  are  susceptible  to  tetanus, 
and  instances  are  recorded  in  which  the  disease  was  appar- 
ently endemic  in  particular  stables.  The  occurrence  of  tet- 
anus among  grooms  and  others  in  close  association  with 
horses  and  cattle  is  probably  due  to  infection  of  insignificant 
wounds  with  soil  containing  the  tetanus  bacillus,  and  not  to 
their  association,  per  se,  with  animals,  as  has  been  suggested 
b)'  some  who  believe  in  the  animal  origin  of  the  tetanus 
virus. 

Dissemination,  Mode  of  Infection. — Though  an  in- 
fectious disease,  tetanus  is  not  communicable  from  person  to 
person,  save  by  direct  inoculation.  The  disease  is  contracted 
through  infection  of  wounds  with  matters  containing  bacillus 
tctani  or  its  spores.  The  commonest  of  such  wounds  are 
those  occurring  about  the  soles  of  the  feet  and  the  palms  of 
the  hands,  though  the  disease  may  result,  and  has  resulted, 
from  the  infection  of  wounds  in  other  parts  of  the  body. 
Frequently  the  wound  is  so  trivial  at  the  time  of  its  reception 
as  not  to  attract  attention,  and  no  notice  is  paid  to  it  until  the 


TETANUS.  159 

remote  effect — general  tetanus — has  set  in.  Often  no  history 
of  injury  in  cases  of  tetanus  can  be  obtained,  either  upon  ex- 
amination of  the  body  or  by  questions  put  to  the  patient ; 
these  cases  are  generally  classed  as  "  idiopathic  tetanus," 
though  it  is  difficult  to  conceive  that  the  disease  can  orig- 
inate without  an  antecedent  trauma  that  has  served  as  the 
portal  of  entry  for  the  specific  micro-organism  ;  or  that  it  can 
be  perfectly  simulated,  and  prove  fatal,  by  some  other  malady 
etiologically  distinct. 

Among  the  negroes  in  the  tropics  and  in  the  southern 
States  tetanus  in  new-born  infants  (tetanus  or  trismus  neon- 
atorum, as  it  is  called)  often  occurs  with  alarming  frequency. 
It  is  practically  always  due  to  direct  infection  of  the  navel 
through  want  of  cleanliness  and  general  carelessness  in  man- 
agement. In  the  southern  States  the  deaths  from  this  cause 
among  negro  infants  have  been  reckoned  at  from  3  to  4  per 
cent,  of  the  total  mortality  from  all  causes.  At  times  in 
Jamaica  20  to  25  per  cent,  of  all  negro  infants  born  die  of 
trismus  neonatorum. 

Prophylaxis. — The  prophylactic  measures  against  tetanus 
include  those  generally  employed  against  wound-infection.  In 
addition  there  should  be  proper  covering  for  the  feet,  for 
the  disease  more  often  results  from  injury  to  the  bare  or  im- 
perfectly shod  and  dirty  feet  by  nails,  splinters  of  wood,  and 
the  like,  than  from  any  other  cause.  Similar  injuries  to  the 
hands  often  result  in  tetanus.  In  short,  all  punctured  or  lac- 
erated wounds  of  the  extremities,  into  which  particles  of  earth 
are  likely  to  have  entered,  should  be  regarded  as  possible 
sites  of  this  particular  infection.  They  should  be  carefully 
cleansed  and  otherwise  cared  for,  no  matter  how  insignificant 
and  trivial  they  may  appear  at  the  time  of  their  reception. 
The  discharges  and  dressings  from  the  wounds  of  tetanus 
patients  contain  the  specific  infective  organism,  and  they 
should  be  considered  as  dangerous.  Dressings  should  be 
burned. 


l6o  HYGIENE    OE   TRANSMISSIBLE   DISEASES. 

ANTHRAX, 

Definition,  Cause,  etc. — An  acute  specific  disease,  due 
to  infection  by  dacilhis  antJiracis. 

As  a  disease  of  animals,  especially  of  herbivora,  it  is  prob- 
able that  anthrax  has  been  known  since  very  early  times.  It 
is  one  of  the  most  widely  distributed  pests,  both  geographi- 
cally and  zoologically,  of  which  we  possess  any  knowledge. 
A  trustworthy  and  complete  conception  of  its  cause,  pathol- 
ogy, modes  of  perpetuation,  dissemination,  and  infection, 
however,  has  been  rendered  possible  only  through  the  appli- 
cation of  precise  methods  of  modern  investigation.  The  evo- 
lution of  our  real  knowledge  of  anthrax  began  with  the  dis- 
cover),^ of  rod-shaped  bodies  in  the  blood  of  animals  dead  of 
the  disease  by  Pollender  in  1855,  and  the  demonstration  that 
these  bodies  stand  in  causal  relation  to  the  malady  by  Davaine 
in  1863. 

Man,  as  well  as  practically  all  domestic  animals,  is  suscep- 
tible to  anthrax.  The  bacillus  of  anthrax  is  a  large,  rod- 
shaped  organism,  with  square  ends  that  may  readily  be 
detected  microscopically,  by  the  ordinary  methods  of  stain- 
ing, in  the  blood  and  internal  organs  of  animals  dead  of  the 
disease,  and  often  in  the  lesions  and  secretions  from  the  site 
of  infection  in  man.  In  the  blood  of  animals  it  is  seen  as 
single  rods  or  as  from  2  to  4  individual  rods  joined  together 
(Fig.  19) ;  it  rarely  occurs  as  longer  threads,  under  these  cir- 
cumstances. Though  readily  forming  spores  under  the  con- 
ditions of  artificial  cultivation,  spores  are  not  found  during 
life  in  the  body  of  the  infected  animal.  Bacillus  aiithracis  is 
not  motile. 

It  can  easily  be  isolated  by  the  usual  culture  methods,  as 
it  grows  readily  and  lu.xuriantly  on  all  nutrient  media  in 
ordinary  u.se  for  bacteriological   purpo.ses. 

Neither  its  morphology  nor  its  appearance  in  cultures  is 
alone  sufficient  for  its  identification,  since  in  each  of  the.se 
respects  it  is  closely  simulated  by  one  or  two  saprophytic 
forms  of  bacteria  that  are  commonly  present  in  the  sDil.  It 
can  be  recognized  with  certainty  by  its  effects  upon  animals. 


ANTHRAX.  l6l 

White  mice,  common  house-mice,  guinea-pigs,  and  rabbits  are 
markedly  susceptible  to  infection  by  it,  and  usually  the  least 
particle  of  a  typical  culture  of  bacillus  anth^acis,  when  de- 
posited beneath  the  skin  of  any  of  these  animals,  suffices  to 
induce  a  septicemia  that  ends  fatally  in  from  eighteen  to 
thirty-six  hours.  The  autopsy  reveals  a  wide-spread  area 
of  edema  about  the  site  of  inoculation  (this  is  most  common 
in  rabbits)  and  the  general  distribution  of  bacilli  throughout 


Fig.  19. — Bacillus  anthracis  in  blood. 

this  area,  as  well  as  their  presence  in  the  blood  and  internal 
viscera. 

Bacillus  antliracis  is  markedly  tenacious  of  life,  particularly 
when  in  the  spore  stage — a  state  into  which  it  enters  as  soon 
as  conditions  arise  that  are  not  conducive  to  its  normal  mul- 
tiplication as  vegetative  cells.  The  spores  of  this  organism 
may  be  dried  for  years  at  ordinary  temperatures — i.  c, 
between  12°  C.  and  40°  C. — without  losing  either  vitality  of 
virulence.  They  withstand  such  detrimental  influences  as 
heat,  cold,  the  antagonism  of  other  bacteria,  etc.,  to  a  remark- 
able degree.  They  germinate,  other  conditions  being  favor- 
able, at  from  12°  C.  to  38°  C.  They  resist  the  temperature 
of  streaming  steam  (100°  C),  at  times,  for  as  long  as  twelve 
minutes  (v.  Esmarch),  though,  as  a  rule,  this  temperature  is 
destructive  to  them  in  from  two  to  four  minutes.  Dried 
11 


1 62  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

spores  are  more  resistant  to  heat  than  are  those  in  a  moist 
condition.  They  are  not  destroyed  by  corrosive  sublimate  in 
I  :  lOOO  solution  in  less  than  twenty-four  hours,  and  they 
have  been  shown  to  resist  the  action  of  5  per  cent,  carbolic 
acid  for  as  long  as  thirty-seven  days.  The  vegetative  forms 
of  this  organism,  when  no  spores  are  present,  are  killed  in 
ten  minutes  by  54°   C. 

From  what  has  been  said  it  is  manifest  that  articles  con- 
taminated by  spore-containing  matters  from  about  animals  or 
man  infected  with  anthrax,  need  to  be  most  carefully  manipu- 
lated in  order  to  eliminate  completely  the  possibility  of  their 
further  disseminating  the  disease.  Herbivora,  omnivora,  and 
certain  carnivora  are  susceptible  to  anthrax,  the  degree  of 
susceptibility  being  greatest  in  herbivora  and  least  in  car- 
nivora. White  rats  are  but  slightly,  if  at  all,  susceptible ; 
many  birds  and,  particularly,  all  cold-blooded  animals  are 
insusceptible. 

As  occurring  in  animals,  anthrax  is  a  septicemia — /.  c,  the 
blood  is  the  principal  field  of  multiplication  of  the  organisms. 
Animals  infected  with  anthrax  frequently  suffer  from  hemor- 
rhages from  the  bowels ;  the  blood  thus  lost  contains  the 
bacilli  in  greater  or  smaller  numbers. 

As  discharged  from  the  body  the  specific  organism  is  not 
in  the  spore-stage,  but  it  readily  enters  this  stage  under  the 
conditions  of  the  soil  that  are  unfavorable  to  its  further  vege- 
tation. In  this  manner  the  soil  over  which  such  cattle  are 
grazing  becomes  infected  and  serves  as  a  means  of  perpetuat- 
ing the  disease  among  the  herd  and  of  disseminating  it  to 
other  cattle  that  may  subsequently  be  pastured  on  the  same 
land.  Infection  commonly  occurs  through  tiny  scratches 
and  wounds  of  the  lips,  tongue,  and  cheeks,  received  by  the 
cattle  while  grazing  over  the  infected  focus.  It  is  likely  that 
the  disease  is  sometimes  carried  by  insects,  such  as  flies,  lice, 
ticks,  etc. 

Anthrax  in  Man. — Anthrax  is  a  comparatively  rare  dis- 
ease in  man  ;  and  man  is  apparently  less  susceptible  to  it 
than  are  most  of  the  domestic  animals. 

It  never  occurs  spontaneous!}-,  but  is  always  the  result  of 


ANTHRAX.  163 

direct  infection.  It  is  most  frequent  in  grooms,  tanners, 
shepherds,  butchers,  herdsmen  in  general,  cattle-dealers,  and 
in  those  whose  occupation  brings  them  in  close  contact  with 
raw  animal-products. 

In  man  the  disease  occurs  as  "  external  anthrax,"  due  to 
the  infection  of  surface-wounds  by  the  specific  morbific  agent, 
and  as  "  internal  anthrax,"  due  to  the  swallowing  or  inspira- 
tion of  dust  contaminated  with  the  spores  of  the  organism. 

In  external  anthrax  (malignant  pustule)  resulting  from 
infected  wounds,  usually  of  the  face,  neck,  hands,  or  forearms, 
the  disease  may  run  its  course  as  a  localized  carbuncle  that 
heals  slowly,  without  constitutional  symptoms,  and  sometimes 
with  but  slight  pain.  Or,  as  is  more  often  the  case,  the  local 
lesion  becomes  surrounded  by  a  progressive  zone  of  edema, 
the  lymphatics  become  involved,  and  symptoms  indicative  of 
general  infection  make  themselves  manifest.  Secondary 
lesions  of  the  stomach  and  intestines  may  occasion  bloody 
vomiting  or  diarrhea ;  those  of  the  brain  are  evidenced  by 
cerebral  disturbance.  A  rapid  extension  of  the  edema  from 
a  local  lesion  of  the  face  or  neck  to  the  larynx  or  thoracic 
cavity  results  in  distressing  dyspepsia,  and  at  times  proves 
fatal.  Death  may  ensue  from  collapse,  due  to  general  infec- 
tion, or  from  either  of  the  secondary  manifestations  men- 
tioned above.  By  both  microscopical  and  culture  methods 
the  specific  bacillus  may  usually  be  detected  at  the  site  of 
infection,  and  in  the  organs  in  those  cases  that  prove  fatal. 
In  cases  that  recover,  the  bacilli  are  often  missed,  or  if  found 
microscopically  they  present  the  appearance  of  degeneration. 
Very  frequently  it  is  impossible  to  cultivate  them  from  the 
local  lesion  in  such  cases,  unless  the  effort  be  made  very 
early  in  the  onset  of  the  disease ;  and  then  mixed  cultures 
— i.  e.,  cultures  of  anthrax  bacilli  together  with  pyogenic 
bacteria  and  ordinary  saprophytic  varieties — are  usually 
obtained. 

A  rarer  manifestation  of  the  disease  is  that  known  as  ina- 
lignant  anthrax  edema.  In  this  form  there  is  no  primary 
papule  or  vesicles  ;  there  is  extensive  edema  of  the  eyelids, 
face,  neck,  hands,  or  arm.     The  edema  may  be  wide-spread 


164  HYGIENE    OE   TRANSMISSIBLE   DISEASES. 

and  result  in  gangrene  of  the  affected  parts.  It  may  follow 
the  constitutional  symptoms.  These  cases  are  frequently 
fatal. 

Internal  anthrax  assumes  two  forms — viz.,  the  intestinal, 
known  as  "  mycosis  intestinalis,"  and  that  which  manifests 
itself  more  especially  through  pulmonary  symptoms  ("  wool- 
sorter's  disease  ").  The  former  occurs  through  the  ingestion 
of  meat  or  milk  from  diseased  animals,  and  through  the  swal- 
lowing of  infected  dust;  while  the  latter  is  seen  among 
workers  in  infected  hair,  hides,  and  wools,  resulting  most 
likely  from  the  inhalation  of  dust  containing  anthrax  spores. 
The  wools  that  are  especially  looked  upon  with  suspicion, 
from  this  standpoint,  are  those  imported  from  Russia  and 
South  America. 

Prophylaxis. — The  most  trustworthy  modes  of  extermi- 
nating the  disease  are  cremation  and  burial  of  the  carcasses 

o 

as  soon  as  possible  after  death.  The  preferable  method  is  the 
latter,  as  the  body  can  be  buried  whole,  and  there  is  thus  less 
liability  of  further  pollution  of  the  soil  with  blood  and  other 
fluids  from  the  tissues  ;  while  for  cremation  or  disinfection  by 
heat  or  chemicals  the  animal  usually  needs  to  be  cut  into 
pieces  of  convenient  size  to  be  handled,  a  process  that  results 
in  the  spreading  about  of  the  infective  agents  through  the 
blood  and  fluids  that  escape  during  manipulation.  The  body 
should  be  buried  nnatt,  not  less  than  six  feet  below  the  sur- 
face. After  this  procedure  the  vegetative  forms  of  the  bacilli 
in  the  blood  and  tissues  are  quickly  destroyed  through  the 
antagonistic  influences  that  accompany  decomposition  of  the 
carcass  in  the  ground.  They  do  not  enter  the  spore-stage,  for 
the  reason  that  under  the  conditions  of  burial  they  are  with- 
out the  free  access  to  oxygen  that  is  all-essential  to  the  proc- 
ess of  spore-formation. 

Of  greater  importance  in  preventing  the  occurrence  of  an- 
thrax among  herds  is  the  method  of  preventive  vaccination. 
Though  all  authorities  are  not  agreed  as  to  the  practical 
benefits  of  this  method,  the  results  reported  by  certain  reli- 
able investigators  are  sufficient  to  warrant  its  being  given  a 
fair  trial.     Thus,  for  instance,  Chamberlain   reports  as  a  re- 


ANTHRAX.  165 

suit  of  experience  with  the  method  of  preventive  vaccination 
in  France,  for  the  twelve  years  ending  with  1893,  that  the 
mortality  from  anthrax  among  3,296,000  vaccinated  sheep 
was  0.96  per  cent.,  whereas  prior  to  the  introduction  of  vac- 
cination it  had  been  10  per  cent.  During  the  same  period 
438,000  head  of  horned  cattle  (bovines)  were  vaccinated  and 
0.34  per  cent,  died  of  anthrax,  the  previous  mortality  from 
this  disease  among  these  animals  having  been  5  per  cent. 
Favorable  results  have  likewise  been  obtained  in  Hungary  and 
in  Russia. 

The  method  has  been  practised  on  a  smaller  scale  with 
satisfaction  at  the  Agricultural  Experiment  Station  at  New- 
ark, Del.,  in  the  neighboring  counties  of  which  anthrax  has 
been  mildly  endemic  for  the  past  two  or  three  years.  The 
disease  has  never  prevailed  in  this  country  to  any  great  ex- 
tent ;  it  is,  in  fact,  considered  to  be  rare  here.  It  is  very  com- 
mon in  South  America,  France,  Russia,  and  Hungary.  The 
method  of  preventive  vaccination  aims  to  induce  a  mild  form 
of  the  disease  by  inoculating  the  animals  with  attenuated  cul- 
tures of  anthrax  bacilli.  Animals  that  have  recovered  from 
this  mild  form  of  anthrax  are  for  a  time,  sufficiently  long  for 
all  practical  purposes,  immune  from  the  disease. 

If  upon  slaughtering  an  animal  it  is  found  to  have  had  an- 
thrax, all  spilled  blood  and  all  soiled  articles  should  be  at 
once  disinfected.  Over  the  blood  that  is  spilled  milk  of  lime 
(fluid  whitewash)  or  5  per  cent,  solution  of  chlorid  of  lime 
should  be  spread.  Instruments  should  be  boiled  and  the 
hands  disinfected  in  3  per  cent,  carbolic  acid  and  washed  thor- 
oughly with  soap  and  water. 

The  flesh  of  anthrax  animals  should  never  be  used  as  food, 
even  in  the  earliest  stages  of  the  disease.  It  should  be  buried 
or  burned,  or  destroyed  by  quick-lime. 

All  hair  and  wool  should  be  disinfected  by  steam.  If  this 
be  impracticable  it  should  be  sorted  moist,  preferably  moist- 
ened with  a  mild  disinfectant.  The  ceiling,  walls,  and  floors 
of  sorting  rooms  should  be  frequently  washed  with  strong 
carbolic-acid  solution  ;  the  walls  should  be  whitewashed  from 
time  to   time.     These   rooms   should  be  well  ventilated,  and 


l66  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

when  the  wools  cannot  be  sorted  in  a  moist  state,  this  should 
be  done  under  hoods  provided  with  specially  strong  outward 
draughts  for  carrying  off  the  dust. 

Workmen  should  be  impressed  with  the  importance  of  per- 
sonal cleanliness,  daily  bathing,  the  frequent  dusting  and 
washing  of  their  clothing,  and  particularly  the  careful  wash- 
ing of  the  hands  before  partaking  of  food.  The  local  secre- 
tions from  malignant  pustule,  and  the  sputum  and  stools  of 
persons  suffering  from  internal  anthrax  are  infectious,  and 
should  be  disinfected.  All  bandages  should  be  burned,  and 
all  instruments  disinfected. 


GLANDERS. 


Definition,  Cause,  etc. — An  infectious  disease  of  horses, 
mules,  and  asses,  communicable  to  man,  and  caused  by  a  spe- 
cific micro-organism — viz.,  bacillus  mallei. 

The  disease  occurs  in  all  countries  and  at  all  seasons.  It 
attracts  more  attention  in  France,  Belgium,  Holland,  Austria, 
Russia,  and  Germany  than  elsewhere.  In  both  men  and 
horses  it  is  remarkable  for  its  fatality. 

The  disease  is  known  as  glanders  when  the  principal  seat 
of  its  activity  is  the  mucous  membrane  of  the  nostrils,  and  as 
farcy  when  it  is  confined  to  the  subcutaneous  lymphatics, 
though  both  expressions  may  occur  simultaneously.  Gland- 
ers is  characterized  by  the  occurrence  of  small  gray  nodules 
(infectious  granulomata)  upon  the  mucous  membrane  of  the 
upper  air-passages,  particularly  of  the  nose.  These  coalesce 
and  ulcerate,  and  there  results  a  profuse  mucopurulent  dis- 
charge from  the  nostrils.  Farcy  is  characterized  by  the 
formation  of  etiologically  similar  granulomata  under  the 
skin,  along  the  course  of  the  lymphatics,  and  in  the  lymphatic 
glands.  These  proceed,  as  a  rule,  to  abscess-formation  and 
suppuration. 

Both  glanders  and  farcy  occur  in  man  ;  the  former  from 


GLANDERS.  1 6/ 

the  deposition  of  the  specific  causative  agent  upon  the  mu- 
cous membrane  of  the  nares,  the  latter  from  its  introduction 
into  wounds  of  the  skin. 

In  man  glanders  may  assume  either  the  acute  or  chronic 
form.  Acute  glanders  is  fatal,  as  a  rule,  in  from  one  to  two 
weeks ;  chronic  glanders  may  exist  for  months  without  of 
necessity  proving  fatal. 

In  acute  farcy  in  man  the  lymphatics  are  conspicuously  in- 
volved, presenting  along  their  course  the  cloudy  nodular 
swellings  known  as  "  farcy  buds."  The  local  site  of  infection 
is  acutely  inflamed,  presenting  the  characters  of  an  acute 
phlegmon.  The  mortality  from  acute  farcy  is  high.  Death 
results  in  from  two  to  three  weeks. 

Chronic  farcy  in  man  is  characterized  by  local  abscesses  in 
the  extremities.  There  is  little  lymphatic  involvement. 
These  abscesses  break  down  and  ulcerate.  The  disease  often 
lasts  for  months,  during  which  time  there  is  frequent  recur- 
rence of  the  local  suppurations.  It  is  not  necessarily  fatal, 
unless  acute  glanders  is  engrafted  upon  it  or  pyemia  super- 
venes. 

The  cause  of  the  disease,  bacillus  mallei,  as  it  is  called,  was 
discovered  by  Loffler  and  Schiitz  in  1882.  It  is  a  short, 
straight  or  slightly  bent,  pointed,  irregularly  staining,  non- 
motile,  non-spore-producing  rod  (Fig.  20)  that  is  found  in  the 
secretions,  in  the  pus,  and  in  the  characteristic  granulomata 
of  animals  and  man  affected  with  the  disease.  It  can  be  iso- 
lated in  culture  on  the  ordinary  nutrient  media,  though  gela- 
tin is  less  adapted  to  this  purpose  than  are  the  other  media 
that  can  be  kept  at  a  higher  temperature.  Its  growth  is  not 
especially  characteristic,  though  on  potato  its  development  is 
simulated  by  but  few,  if  any,  other  organisms.  Here  it  grows 
as  a  moist,  brownish,  amber-  or  honey-colored  layer  that  grad- 
ually assumes  a  deeper  color  as  development  proceeds. 

It  is  destroyed  in  five  minutes  by  a  temperature  of  55°  C.  ; 
in  five  minutes  by  5  per  cent,  carbolic  acid  and  in  two  min- 
utes by  I  :  1000  corrosive  sublimate.  It  is  killed  in  a  few 
days  by  drying.  It  has  been  known  to  resist  putrefaction 
for  a  long  time.     Boiling  water  instantly  kills  them — a  prac- 


l68  HYGIEXE    OF   TRANSMISSIBLE  DISEASES. 

tical  point  of  value  to  be  remembered  in  cleaning  up  the 
stalls  of  animals  or  the  beds  of  men  affected  with  the  disease. 
Horses, 'asses,  mules,  lions,  tigers,  field-mice,  guinea-pigs,  and 
cats  are  susceptible  to  glanders.  Rabbits  are  but  slightly 
susceptible,  and  dogs  and  sheep  less  so.  White  mice,  com- 
mon gray  mice,  bovines,  hogs,  and  rats  are  insusceptible. 
Man,  as  said,  is  susceptible  to  this  variety  of  infection. 

Beyond  the  appearance  of  the  characteristic  granulomata 
in  the  spleen,  field-mice  dead  after  subcutaneous  inoculation 
with  this  organism  present  none  of  the  lesions  characteristic 
of  the  disease  in  the  horse.    The  spleen  is  enlarged,  and  often 


Fig.  20. — Bacillus  mallei  from  artificial  culture. 

quite  covered  with  tiny  gray  nodules  having  something  the 
appearance  of  miliary  tubercles.  The  pathological  lesions 
and  clinical  course  of  the  disease  after  subcutaneous  inocula- 
tion of  guinea-pigs  are  much  more  typical.  The  animal  lives 
for  from  six  to  ten  weeks,  during  which  time  the  joints  of  the 
extremities  become  infiltrated,  swollen,  and  stiff;  the  testicles 
become  very  much  distended,  often  suppurating  and  break- 
ing til  rough  the  skin  ;  and  there  is  the  characteristic  muco- 
purulent discharge  from  the  nostrils,  secondary  to  ulceration 
of  the  nasal  mucous  membrane.  The  lungs,  kidneys,  liver, 
and  spleen,  especiall}'  the  last,  usually  contain  the  minute. 


GLANDERS.  1 69 

gray  nodules — the  glanders  granulomata.     The  bacillus   of 
glanders  may  be  recovered  from  all  the  lesions. 

The  most  trustworthy  diagnostic  test  for  glanders  is  that 
recommended  by  Strauss.  It  consists  in  the  introduction  of 
a  bit  of  the  suspected  culture  or  tissue  into  the  peritoneum 
of  a  male  guinea-pig.  If  the  material  used  be  from  a  case  of 
glanders  the  animal's  testicles  begin  to  swell  in  about  thirty 
hours,  the  skin  over  them  becomes  red  and  shining,  and 
desquamation  occurs  ;  evidence  of  incipient  suppuration  is 
manifest,  and  there  results  a  purulent  orchitis  that  ultimately 
breaks  through  the  skin. 

The  modern  method  used  by  most  progressive  veterinarians 
for  the  diagnosis  of  incipient  glanders  in  horses  is  by  the  use 
of  mallein.  Mallein  is  the  filtered  product  of  growth  of  the 
glanders  bacillus  in  fluid  media.  When  injected  into  animals 
affected  with  the  disease,  even  in  so  early  a  stage  as  to  defy 
recognition  by  other  methods  of  inspection,  there  results  a 
striking  constitutional  reaction  that  is  signalized  by  sudden 
but  temporary  rise  of  temperature ;  whereas  a  similar  injec- 
tion is  sustained  by  healthy  animals,  or  those  not  affected 
with  glanders,  without  such  a  result. 

Modes  of  Dissemination,  Portals  of  Infection. — 
Glanders  is  commonly  disseminated  among  animals  through 
direct  contact  between  the  healthy  and  diseased,  the  source 
of  infection  being  in  most  instances  the  discharges  from  the 
muzzle.  It  may  be  carried  by  flies,  hce,  ticks,  and  similar 
insects.  Farcy  may  result  from  the  extension  of  the  disease 
from  its  primary  site  in  the  nose,  along  the  lymphatics  ;  or  it 
may  result  primarily  from  infection  of  wounds  of  the  hide. 

In  man  the  disease  is  the  result  of  direct  infection,  glanders 
resulting  from  the  deposition  of  infective  matters  upon  the 
mucous  membrane  of  the  upper  air-passages,  and  farcy  from 
the  infection  of  wounds  of  the  skin. 

In  the  ordinary  sense  of  the  word,  the  disease  is  not  con- 
tagious, though  it  is  not  improbable  that  the  air  about  the 
glanderous  horse  that  is  snorting  or  coughing  contains  the 
virus,  and  may  cause  the     isease  if  inspired. 

In    man    the    disease    is    most   frequently  encountered    in 


IJO  HYGIEXE    OF   TRANSMISSIBLE  DISEASES. 

grooms,  horse-dealers,  and  others  coming  in  close  association 
with  horses,  mules,  and  asses. 

Prophylaxis. — In  neighborhoods  that  are  free  from  the 
disease,  all  imported  horses,  mules,  and  donkeys  should  be 
quarantined  until  carefully  inspected  by  a  competent  veterin- 
ary surgeon.  All  animals  suffering  from  the  disease  should 
be  killed.  They  should  never  be  permitted  to  mingle  in  any 
way  with  healthy  animals,  or  even  kept  in  close  proximity 
to  them,  after  the  diagnosis  is  established.  Attendants  who 
have  been  in  charge  of  the  diseased  animals  should  not  be 
permitted  to  handle  the  healthy  ones  until  after  thorough 
cleansing  and  disinfection  of  their  clothing  and  hands. 

Attendants  should  look  with  suspicion  upon  all  horses 
having  a  discharge  from  the  nose  or  corded  nodules  under 
the  skin.  They  should  guard  carefully  against  infecting  abra- 
sions of  the  hands,  however  slight  they  may  seem,  with  dis- 
charges from  diseased  horses. 

Bandages,  dressings,  and  instruments  that  have  been  used 
about  animals  or  man  affected  with  glanders  are  capable  of 
carrying  the  infection,  unless  rendered  harmless  by  thorough 
disinfection. 

The  stalls  from  which  glanderous  animals  have  been  re- 
moved should  be  thoroughly  cleansed  with  boiling  water ; 
the  scrapings  and  sweepings  should  be  scalded  and  burned. 
The  droppings  from  such  animals  should  be  scalded  or 
burned.     The  refuse  of  fodder  should  be  scalded  or  burned. 

The  harness,  particularly  the  bit,  should  be  either  thor- 
oughly scalded,  or  soaked  in  5  per  cent,  carbolic  acid  for  a 
few  hours,  after  which  it  should  be  scrubbed  with  soap  and 
hot  water,  and  dried  before  being  used  on  a  healthy  animal. 

The  carcasses  of  dead  animals  should  be  deeply  buried  or 
burned. 


ACTINOMYCOSIS.  171 


ACTINOMYCOSIS. 

Definition,  Cause,  etc. — A  chronic  infectious  disease  of 
cattle  and  man  that  results  from  the  development  within  the 
tissues  of  the  actinoinyces  or  ray  fungus. 

Pathologically,  the  disease  is  characterized  by  the  develop- 
ment in  the  tissues  in  which  the  fungus  is  growing — most 
frequently  those  of  the  tongue  or  lower  jaw — of  granuloma- 
tous masses  that  in  some  particulars  suggest  the  tuberculous, 
in  others  the  osteosarcomatous  processes.  In  the  more 
rapidly  growing  of  these  tumors  suppuration,  resulting  in 
cavities  and  fistulous  formations,  may  occur. 

If  the  pus  from  a  case  of  actinomycosis  be  spread  upon  a 
glass  slide  or  allowed  to  flow  down  the  inside  of  a  test-tube, 
it  will  be  seen  by  transmitted  light  to  contain  numerous  small, 
white,  yellowish,  yellowish-green,  or  brownish  points,  easily 
discoverable  to  the  naked  eye  and  having  somewhat  the 
appearance  of  fine  grains  of  sulphur  or  sand.  If  these  be 
picked  out,  gently  squeezed  between  a  slide  and  cover-slip, 
and  examined  with  a  moderate  power  of  the  microscope,  they 
will  be  found  to  consist  of  a  felt-Hke  mycelium  of  a  roughly 
rosette  shape.  At  the  center  the  mass  is  coarsely  granular 
and  presents  numerous  oval  and  spherical  spore-  or  coccus- 
like structures.  About  this  center  is  a  tolerably  broad, 
irregular  zone  of  straight,  curved,  and  branched  pear-  or 
club-shaped  radii. 

From  man  these  fungous  tufts  give  the  sensation,  when 
squeezed  under  the  cover-slip,  of  small  particles  of  tallow  or 
fatty  tissue ;  whereas  from  animals  they  feel  gritty,  due  to  the 
deposition  of  lime-salts. 

Staining  is  employed  only  for  the  detection  of  certain 
minute  structural  details  that  are  not  necessary  for  diagnosis. 
In  unstained  preparations  the  appearance  of  the  tufts  is  char- 
acteristic. If  the  structure  be  obscured  by  a  deposit  of  cal- 
careous matter,  this  may  readily  be  dissolved  away  with 
dilute  acetic  acid,  without  injury  to  the  structure  of  the 
fungfus. 


172  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

It  can  be  cultiv-ated  on  practically  all  the  ordinary  nutrient 
media,  especially  glycerin  agar-agar,  coagulated  blood-serum, 
and  sterilized  moistened  bread-crumbs.  In  cultures  the  branch- 
ing mycelia  and  the  round  or  oval  coccus-  or  spore-like  bodies 
are  formed,  but  the  club-shaped  bodies  seen  in  the  pus  are 
less  common,  though  they  do  occasionally  present  under 
these  circumstances. 

Notwithstanding  the  fact  that  several  trustworthy  investi- 
gators have  reported  positive  results  from  the  inoculation  of 
animals  with  this  fungus,  Bostrom,  who  has  contributed  so 
liberally  to  our  knowledge  of  the  subject,  still  doubts  that 
the  disease  has  ever  been  really  reproduced  in  that  way.  He 
claims  that  the  tumefactions  observed  in  the  cases  reported 
as  successful  were  not  due  to  a  multiplication  of  the  fungus, 
but  \vere  simply  non-progressive  points  of  proliferated  tissue, 
by  which  the  fungous  masses  used  for  inoculation  have  been 
encapsulated.  The  proof  of  its  transmissibility  by  inocula- 
tion is  as  yet  incomplete.  The  actinomyces  fungus  is  a 
streptothrix. 

Actinomycosis  occurs  in  bovines,  horses,  and  hogs.  Its 
most  common  seat  of  development  is  the  tongue  and  adjacent 
tissues  of  the  jaws,  particularly  the  lower  jaw.  It  may  occur 
in  the  lips,  cheeks,  palate,  pharynx,  nose,  larynx,  trachea, 
lungs,  skin,  and  subcutaneous  tissues. 

From  the  frequency  of  its  occurrence  in  the  tongue  and 
jaws,  and  from  the  induration,  tumefaction,  and  stiffening 
that  it  occasions  it  is  popularly  spoken  of  as  "  lump-jaw,"  or 
"  lumpy  jaw,"  and  "  wooden  tongue."  It  attacks  cattle  of  all 
ages,  and  is  usually  considered  to  be  incurable. 

In  man  actinomycosis  is  a  rare  disea.se.  When  occurring 
it  is  most  frequently  seen  as  a  disea.se  of  the  lower  jaw.  The 
tumor  rarely  begins  in  the  bone  itself,  but  usually  at  its 
periphery,  manifesting  itself  as  a  lum])  in  the  submaxillary, 
submental,  or  pretracheal  region.  Metastases  from  the  pri- 
mary growth  are  not  uncommon.  The  disease  may  occur  in 
the  lungs,  from  inhalation  of  the  fungus,  resulting  in  pneu- 
monic patches,  suppuration,  hemorrhage,  and  cavity-forma- 
tion.    The  sputum  of  such  cases  contains  the  fungus.     Clin- 


A  C  TINOM  YCOSIS.  1 7  3 

ically,  and  in  certain  anatomical  features,  these  cases  are  very 
suggestive  of  chronic  pulmonary  tuberculosis. 

Invasion  of  the  intestinal  tract  may  also  occur  in  man.  In 
this  expression  of  the  disease  small  nodules  of  about  the  size 
of  a  pea  are  seen  in  the  mucous  membrane  and  submucous 
tissues  of  the  gut.     These  soften,  ulcerate,  and  either  heal  or, 


Fig.  21. — Actinomyces  fungus  ("  ray  fungus")  ;  left,  as  seen  in  tissues  under  low 
magnifying  power  ;  right,  a  fungus  mass  examined  fresh  under  higher  mag- 
nifying power. 

as  is  more  commonly  the  case,  perforate  into  the  peritoneum, 
bladder,  or  through  the  abdominal  wall. 

Dissemination,  Portals  of  Infection. — There  is  no 
positive  evidence  that  the  disease  is  transmitted  from  animal 
to  animal,  or  from  animal  to  man,  or  vice  versa.  It  seems 
probable  that  both  man  and  animals  receive  the  virus  from 
the  same  external  source. 

The  belief  is  that  the  fungus  is  a  parasite  upon  certain 
cereals,  and  that  it  gains  access  to  the  animal  through 
wounds  of  the  buccal  mucous  membranes,  through  abrasions 
of  the  skin,  or  by  way  of  carious  teeth.  Barley  is  the  grain 
that  is  viewed  with  most  suspicion.  Infection  occurs  most 
frequently,  in  all  probability,  during  feeding,  though  some 
believe  it  to  occur  occasionally  through  inspired  dust  and 
through  water  containing  the  fungus  or  its  spores. 


174  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

Prophylaxis. — Since  the  disease  is  not  readily  trans- 
mitted from  animal  to  animal,  or  animal  to  man,  by  either 
ordinar}'  contact  or  by  inoculation  ;  and  since  nothing  is 
positively  known  of  the  fungus  outside  the  animal  body 
(except  in  artificial  culture),  it  is  manifest  that  our  knowledge 
is  too  limited  to  permit  of  the  formation  of  trustworthy  and 
rational  prophylactic  rules. 

It  is,  of  course,  safer  to  regard  subjects  of  the  disease 
as  dangerous  and  to  isolate  them,  therefore ;  it  is  advisable 
to  burn,  scald,  or  otherwise  disinfect  articles  polluted  with 
the  discharges  from  such  animals  or  persons. 


MADURA  FOOT. 

{Fungus  Disease  of  India;  Mycetoma.) 

Because  of  the  existence  of  certain  points  of  resemblance 
between  actinomycosis  and  Madura  foot,  it  is  proper  to  sum- 
marize the  essential  features  of  the  latter  disease  at  this 
place. 

Mycetoma,  Madura  foot,  or  fungus  disease  of  India,  as  the 
disease  is  called,  is  a  chronic  affection  occurring  in  the  foot, 
and  occasionally  in  the  hand,  that  is  found  endemically  in 
many  parts  of  India.  It  is  not  supposed  to  originate  outside 
of  India,  though  cases  of  the  disease  have  been  observed  in 
Italy,  Morocco,  America,  and  elsewhere.  In  many  instances 
these  were  imported. 

It  is  characterized  by  local  tumefactions  of  the  foot  or 
hand.  It  is  usually  found  in  the  foot,  and  does  not  pass  be- 
yond the  metatarsal  articulation,  though  occasionally  it  is 
seen  to  include  the  leg  and  even  reach  as  high  up  as  the 
thigh.  Anatomically  this  tumor  in  many  respects  sug- 
gests that  resulting  from  the  invasion  of  the  tissues  by  the 
actinomyces  fungus,  though  there  is  sufficient  evidence  to 
ju.stify  the  opinion  that  the  two  diseases  are  etiologically 
distinct. 


MADURA   FOOT.  175 

It  originates  in  the  toes  or  in  the  loose  cellular  tissues 
about  the  dorsum  of  the  foot.  It  gradually  involves  the 
deeper  structures,  reaching  quite  to  and  affecting  the  bones. 
Numerous  sinuses,  which  discharge  a  stinking  watery  pus, 
lead  from  the  surface  to  the  deeper  structures.  The  affected 
part  is  very  much  enlarged,  hard,  tense,  and  painful.  It  never 
attacks  both  feet  simultaneously.  It  is  not  communicable 
from  person  to  person,  and  is  not  apparently  auto-infective. 

The  hand  is  very  much  less  frequently  attacked  than  the 
foot.  The  agricultural  classes  are  much  more  liable  to  it 
than  are  other  classes  of  the  community.  When  fatal,  death 
results  from  marasmus.  If  the  affected  member  be  ampu- 
tated sufficiently  early,  health  is  generally  regained. 

Ktiology. — Two  expressions  of  the  disease  occur — 
namely,  the  "  white  "  and  the  "  black  "  mycetoma.  In  both 
infections  the  tumors  are  characterized  by  the  presence  of 
numerous,  minute  granules  about  the  size  of  a  pin-head.  In 
the  white  mycetoma  these  granules  are  white  or  yellowish  in 
color ;  in  the  black  mycetoma  they  are  dark-brown  or  at 
times  quite  black  in  color.  By  microscopical  and  bacterio- 
logical methods  these  granules  are  found  to  consist  of  fun- 
goid masses.  The  white  mycetoma  has  been  closely  studied 
by  Bristowe,  Carter,  Kanthack,  Boyce  and  Surveyor,  Adami, 
and  others,  and  there  is  a  general  agreement  of  opinion  that 
it  is  in  many  respects  very  like  the  actinomyces  fungus.  The 
fungus  isolated  by  Vincent  from  white  mycetoma  is  described 
by  him  as  a  mycetial  streptothrix  that  grows  readily  at  body- 
temperature  on  nutrient  media  containing  sugar  and  glycerin. 
It  develops  especially  well  in  vegetable  infusions.  It  is  not 
pathogenic  in  animals. 

From  the  black  mycetoma  a  fungus  has  been  isolated  by 
Bristowe,  Hogg,  Bassini,  Kanthack,  Boyce  and  Surveyor, 
Wright,  and  others,  whose  morphology,  color,  and  cultural 
peculiarities  distinguish  it  at  once  from  that  isolated  from  the 
white  form  of  the  disease.  It  is,  therefore,  likely  that  there 
are  concerned  in  the  production  of  this  malady  two  distinct 
fungi.^     The  inoculation  of  animals  with  the  fungus  obtained 

^  An  excellent  description  of  the  black  mycetoma,  as  well  as  a  review  of 


176  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

from  the  black  mycetoma  was,  as  in  the  case  of  that  from 
the  white  mycetoma,  negative  in  results.  The  two  varieties 
of  fungi  do  not  appear  together  in  the  same  case. 

The  disease  is  believed  to  occur  in  man  through  the  access 
of  the  causative  agents  to  wounds  of  the  feet  or  hands. 

It  is  very  much  more  common  among  the  Hindoos  than 
among  the  Europeans  or  Indo-Europeans.  Not  a  single 
case  of  the  disease  among  Europeans  or  Indo-Europeans  has 
been  observed  in  India  during  the  past  forty  years  (Hirsch). 
It  is  most  common  between  the  ages  of  twenty  and  twenty- 
five  years.  It  is  extremely  rare  in  the  very  young  and  in 
the  very  old.     It  is  more  common  in  males  than  in  females. 


SMALL-POX* 

Definition,  Cause,  etc. — An  acute,  infectious,  highly 
contagious  disease  that  is  characterized  by  an  eruption  upon 
the  skin  and  exposed  mucous  surfaces.  The  eruption  passes 
through  the  papular,  vesicular,  and  pustular  stages  in  turn, 
and  finally  heals  under  a  scab.  The  disease  is  especially 
communicable  during  the  convalescent  period,  when  des- 
quamation is  actively  in  progress. 

Though  several  micro-organisms,  both  of  bacterial  and 
protozoal  nature,  have  been  detected  in  the  pathological 
lesions  of  small-pox,  none  of  them  have  been  proven  to 
stand  in  causal  relation  to  the  disease.  The  cause  of  small- 
pox is  as  yet  undiscovered. 

Historical. — According  to  the  exhaustive  researches  of 
Hirsch,  the  origin  of  the  disease  cannot  definitely  be  made 
out,  though  the  earliest  records  of  it  are  found  in  India  and 
Central  Asia.  The  first  medical  literary  contribution  on 
small-pox  is   that  of  Rogers  in  the  tenth  centuiy.     Incon- 

the  literature  on  the  subject,  is  given  by  Wriglit  in  the  Joitnial  of  Experi- 
mental Medicine,  1898,  vol.  iii.,  p.  421.  The  illustrations  in  this  article  are 
of  special  merit. 


SMALL-POX.  177 

testable  records  of  the  disease  in  Europe  date  from  the  elev- 
enth and  twelfth  centuries.  It  was  introduced  into  North 
America  by  the  Spaniards  in  the  sixteenth  century. 

Small-pox  has  appeared  among  practically  all  peoples  on 
the  globe,  and  still  appears  with  varying  degrees  of  severity, 
more  especially  in  localities  where  vaccination  is  not  system- 
atically practised.  It  attacks  all  ages,  and  is  particularly 
fatal  during  the  early  years  of  life.  Osier  states  that  86  per 
cent,  of  all  deaths  observed  by  him  during  the  severe  epi- 
demic in  Montreal  in  1885  occurred  in  children  under  ten 
years  old.  Males  and  females  are  affected  with  practically 
equal  frequency.  Negro  and  other  colored  races  seem  to  be 
more  susceptible  than  are  whites. 

Excessive  fatality  has  been  observed  to  follow  the  first  ex- 
posure of  aboriginal  races  to  this  disease,  such,  for  instance, 
as  that  seen  among  the  early  settlers,  American  Indians,  and 
Mexicans  after  the  importation  of  small-pox  into  this  country 
by  the  Spaniards  in  the  sixteenth  century.  It  is  much  more 
prevalent  during  the  cold  than  during  the  warm  months  of 
the  year  in  temperate  climates. 

Dissemination. — In  the  majority  of  cases  the  disease 
appears  to  be  directly  transmitted  from  the  sick  to  the  well 
through  the  air.  Persons  unprotected  by  vaccination  appar- 
ently contract  the  disease  by  simply  breathing  the  air  of  the 
room  in  which  the  patient  is  confined.  There  is  no  evidence 
that  the  disease  is  transmitted  by  food  or  through  wounds ; 
neither  is  there  any  evidence  to  the  contrary.  Persons  who 
have  been  in  contact  with  small-pox  patients,  all  articles  used 
about  the  patient,  such  as  body-  and  bed-clothing,  eating- 
utensils,  carpets,  furniture,  letters,  etc.,  and  vehicles  in  which 
the  sick  may  have  been  transported,  are  capable  of  conveying 
the  contagion. 

The  period  of  highest  infectivity  is  believed  to  be  during 
the  stage  of  desquamation,  when  the  morbific  agent,  of  what- 
soever nature  it  may  be,  is  disseminated  throughout  the  air 
with  the  fine  particles  of  epidermis  that  the  patient  sheds. 
The  disease  is  probably  contagious  sooner  than  this,  but  just 
how  soon  is  not  definitely  determined. 
12 


1/8  HYGIENE    OF   TRANSMISSIBLE    DISEASES. 

Prophylaxis. — For  the  prevention  and  eradication  of 
small-pox  s}'stematic  (compulsory  if  need  be)  vaccination  so 
overshadows  in  importance  all  other  means  as  to  make  it  the 
prophylactic  measure  /rt:r  excellence  against  this  pest.  The 
isolation  of  the  patient,  the  disinfection  or  destruction  by 
burning  of  all  clothing  and  other  objects  that  have  been  in 
contact  with  him,  the  disinfection  of  his  room,  the  anointing 
of  his  body  with  antiseptic  oils  during  the  dangerous  stage 
of  desquamation,  etc.,  are  precautions  never  to  be  ignored  in 
efforts  to  pre\'ent  the  spread  of  the  disease  ;  but  they  are  as 
naught  in  efficiency  as  compared  with  the  successful  vaccina- 
tion of  all  those  with  whom  the  small-pox  patient  or  con- 
valescent is  likely  to  be  in  association  (see  and  compare 
accompanying  charts  of  Prussia  and  Austria,  Charts  13 
and   14. 

To  meet  the  demands  of  large  centers  of  civilization  in 
which  sporadic  cases  and  mild  outbreaks  of  small-pox  are 
from  time  to  time  occurring,  there  should  be  hospitals  or 
lazarettos  especially  equipped  for  the  management  of  acute, 
infectious  diseases.  These  should  be  provided  with  proper 
facilities  for  isolating  the  cases,  for  disinfecting  the  clothing, 
and  for  frequent  cleansing  and  disinfecting  of  the  entire  walls, 
ceilings,  floors,  and  furniture  of  the  wards  or  separate  rooms. 
The  personnel  of  such  hospitals  should  comprise  competent 
physicians,  well  versed  in  the  laws  of  preventive  medicine, 
and  an  adequate  corps  of  nurses  specially  trained  in  the 
management  of  infectious  diseases,  all  of  whom  should  have 
been  successfully  vaccinated.  Sporadic  cases  of  small-pox 
should  be  sent  to  such  hospitals  at  the  earliest  possible  mo- 
ment after  the  diagnosis  is  established.  Hospitals  for  this 
purpose  should  be  provided  with  special  observation  wards 
in  which  doubtful  cases  may  be  placed  until  the  true  nature 
of  the  disca.se  is  definitely  made  manifest. 

For  the  welfare  of  the  comnumity  at  large,  too  much 
stress  cannot  be  laid  upon  the  importance  of  prom])t  notifica- 
tion of  the  existence  of  contagious  di.sease.  It  is  only 
through  tlie  full   co-operation  of  physicians  in  these  matters 


SMALL-POX. 


1 79 


Chart  13. — Progress  of  small-pox  in  Prussia  before  and  after  the  en- 
forceme7it  of  general  vaccination.  Death-rate  per  100,000  of  popu- 
lation, 1 8 46- 1 886. 


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Charts  13  and   14  are  after  Schulz  :   Impfung,  Impfgeschdft  und  Impftechnik, 

Berlin,  1891. 


l8o  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

that  the  municipal  health  authorities  are  enabled  to  perform 
the  functions  of  their  office  properly. 


VARICELLA 

(  Chicken-pox. ) 

Definition,  Cause,  etc. — An  acute,  specific,  febrile,  dis- 
order that  is  characterized  by  a  peculiar  vesicular  eruption 
upon  the  skin.  The  cause  is  not  known.  It  is  rarely  severe, 
and  is  one  of  the  common  diseases  of  childhood  ;  it  is  espe- 
cially seen  in  children  under  five  years  of  age,  though  it  may 
occur  in  older  persons. 

It  prevails  in  the  autumnal  months.  It  is  seen  both  as 
isolated  cases  and  as  epidemic  outbreaks.  It  is  not  appar- 
ently related  etiologically  to  small-pox,  and  an  attack  of 
chicken-pox  in  no  way  protects  against  small-pox,  and  vice 
versa.  Instances  are  recorded  in  which  both  diseases  have 
occurred  in  the  same  individual  within  a  short  time  of  each 
other. 

It  is  markedly  contagious,  but  the  channels  through  which 
it  is  especially  transmitted  are  not  definitely  determined. 
The  contagion  appears  to  be  air-borne,  and  also  seems  to  be 
capable  of  being  carried  by  fomites. 

Prophylaxis. — The  disease  is  contagious  from  its  onset 
to  its  finish.  The  prophylactic  measures  that  are  adopted, 
when  adopted  at  all,  consi-st  in  the  isolation  of  the  patient, 
though,  as  a  rule,  the  disease  is  regarded  as  so  benign,  and 
as  a  disease  through  which  children  are  of  necessity  liable  to 
pass,  that  few  strict  measures  are  adopted  for  the  prevention 
of  its  spread. 

The  complications,  or  rather  the  unusual  manifestations, 
of  varicella  are  subjects  more  for  works  upon  clinical  medi- 
cine than  for  sketches  of  this  character. 


MEASLES.  151 

MEASLES. 

Definition,  Cause,  etc. — An  acute  febrile  disorder  char- 
acterized by  the  occurrence  of  coiyza  and  an  eruption  upon 
the  skin  of  small  red  papules  that  ultimately  coalesce  into 
irregularly  round  or  crescentic  blotches. 

Measles  is  one  of  the  most,  if  not  the  most,  contagious  of 
the  acute  exanthemata.  Its  cause  has  not  yet  been  deter- 
mined. • 

It  is  a  disease  of  the  first  five  years  of  childhood,  though 
it  is  also  occasionally  observed  in  adults.  The  rarity  of 
measles  in  adults  is  probably  to  be  explained  through  the 
fact  that  practically  all  children  pass  through  the  disease,  and 
one  attack  usually  protects  against  subsequent  infection, 
though  this  is  not  always  the  case,  as  instances  are  recorded 
in  which  more  than  one  occurrence  of  the  disease  has  been 
observed  in  the  same  individual.  It  is  endemic  in  all  civilized 
countries  and  occasionally  breaks  out  in  epidemic  form.  It 
is  a  disease  of  late  autumn  and  early  spring. 

It  is  directly  communicable  from  the  sick  to  the  well ;  the 
secretions  from  the  catarrhal  surfaces  and  the  exfoliated  epi- 
dermis are.  capable  of  infection,  and  the  disease  may  be  car- 
ried by  fomites  and  by  persons. 

As  in  the  case  of  varicella,  vigorous  efforts  are  rarely  made 
to  prevent  the  spread  of  measles.  It  is  so  eminently  conta- 
gious that  the  usual  efforts  are  considered  of  but  little  avail. 
The  patient  should  be  isolated,  and  only  the  nurse  and  physi- 
cian should  have  access  to  the  sick-room.  The  napkins, 
towels,  dishes,  bed-  and  body-clothing  should  be  disinfected 
before  they  are  permitted  to  be  taken  from  the  room.  After 
recovery  the  room  should  be  thoroughly  disinfected  and 
cleaned,  and  well  aired. 

Rubeola  {Rdtheln  or  Germajt  measles)  partakes  of  certain 
of  the  characteristics  of  both  measles  and  scarlatina,  though 
immunity  to  it  is  not  conferred  by  an  attack  of  either  of  these 
diseases.  Its  cause  is  not  known.  It  is  considered  a  dis- 
tinct, specific,  febrile  disorder.  It  is  characterized  by  an 
eruption.     It  is  communicable  by  direct  contact  between  the 


1 82  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

sick  and  the  well.  It  is  less  contagious  than  measles.  It  is 
more  common  in  youth  than  in  childhood.  It  often  occurs 
in  epidemic  form. 

In  other  respects,  what  has  been  said  for  measles  applies 
also  to  rubeola,  except  perhaps  that  its  spread  is  more  readily 
controlled  than  is  that  of  measles. 


SCARLET  FEVER. 

Definition,  Cause,  etc. — An  acute,  specific  fever  char- 
acterized by  the  occurrence  of  erythematous  rash  upon  the 
skin,  and  accompanied  by  angina  of  varying  degrees  of 
severity.  Its  cause  is  not  known.  The  various  bacteria  and 
protozoa  that  have  been  described  as  occurring  in  these  cases 
have  not  been  proved  to  stand  in  causal  relation  to  them. 

Because  of  the  constant  presence  of  streptococci  in  the 
angina  that  is  associated  with  scarlatina,  and  because  of  the 
occasional  detection  of  this  organism  in  the  internal  viscera 
as  well,  it  is  held  by  some  that  the  streptococcus  found  stands 
in  causal  relation  to  the  malady.  This  opinion  is  not,  how- 
ever, generally  accepted,  principally  for  the  reasons  that  the 
streptococci  discovered  do  not  differ  from  the  ordinary  pyo- 
genic streptococcus,  and  that  the  disease  is  in  all  respects  dif- 
ferent from  the  usual  results  of  infection  by  this  organism.  It 
has  been  suggested  that  the  clinical  manifestations  of  the  dis- 
ease as  well  as  the  anatomical  lesions,  except  those  in  the 
throat,  are  the  result  of  absorption  of  toxins  produced  by 
the  streptococci  located  in  the  diseased  tonsils,  and  that  the 
disease  is  not  necessarily  a  result  of  general  sy.stemic  infec- 
tion ;  this  view  also  is  not  generally  accepted.  In  the  pres- 
ent .state  of  our  knowledge  it  can  only  be  said  that  the  ex- 
citing cause  of  scarlet  fever  is  as  yet  unknown,  and  that  up 
to  date  there  have  not  been  any  suggestions  upon  this  point 
that  have  met  with  general  acceptance. 

It  is  contagious,  though  less  so  than  measles.     It  occurs 


SCARLET  FEVER. 


83 


both  sporadically  and  as  epidemic  outbreaks.  It  is  most  com- 
mon during  the  first  ten  years  of  life,  though  it  is  also  seen 
in  adults.  It  is  not  very  common  in  children  under  one  year 
The  accompanying  table  (Table  X.)  (from  Goodall 


of  age. 


Table  X. — Scar/atina  at  the  Hospitals  of  the  Metropolitan  Asy- 
lum'' s  Board,  London.  Arranged  according  to  ages  (^Good- 
all  and  Washbourn^^  : 


Cases 
admitted. 

Deaths. 

Fatality 
per  cent. 

Under  5  years 

5  to  10     " 
10  to  15     " 
15  to  20     " 
20  to  25     " 
25  to  30     " 
30  to  35     " 
35  to  40     " 
40  years  and  u 

pw 

ar 

d 

23,072 

33,647 

14,399 

5,319 

2,509 

1,215 

665 

281 

243 

4052 

1789 

345 

139 

65 

38 

31 

16 

15 

17.6 

5-3 
2.4 
2.6 

2.6 
31 

4-7 
5-7 
6.2 

Total  . 

81,350 

6490 

8.0 

and  Washbourn)  strikingly  illustrates  these  points.  It  is  a 
disease  of  autumn  and  winter  (see  diagram  in  Section  I.,  un- 
der the  heading  of  Predisposing  Influence  of  Season).  It  is 
known  among  all  peoples  in  all  countries. 

In  mild  outbreaks  the  fatality  varies  from  4.2  to  10  per 
cent,  while  in  severe  epidemics  it  often  reaches  15  and  20  per 
cent,  of  those  affected. 

Dissetnination. — Scarlet  fever  is  probably  contagious  at 
all  periods,  but  it  appears  to  be  especially  so  during  the 
stage  of  desquamation.  The  morbific  agent,  whatever  it  may 
be,  is  very  tenacious  of  life  and  pathogenic  powers,  and  may 
cling  to  clothing,  furniture,  and  the  like  for  very  long  periods, 
retaining  its  power  to  reproduce  the  disease  under  favorable 
circumstances. 

Physicians,  nurses  and  attendants,  members  of  the  family, 
and  fomites  may  carry  the  disease.  Contagion  may  also  occur 
directly  through  the  air  of  the  sick-room,  and  this  is  perhaps 
the  commonest  mode  of  transmission,  especially  when  the  air 
is  laden  with  the  fine  dust-like  particles  of  epidermis  shed  by 

^  Infectiozis  Diseases,  by  Goodall  and  Washbourn,  Philadelphia,  1896. 


184  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

the  patient  during  the  stage  of  desquamation.  In  the  earliest 
stages — /.  c,  before  the  development  of  the  eruption — it  seems 
to  be  less  contagious  than  later.  There  is  no  evidence  that 
the  disease  is  conveyed  by  water.  There  are  a  number  of 
instances  in  which  it  has  been  carried  and  more  or  less  widely 
disseminated  by  infected  milk.  By  some  writers  the  milk  of 
cows  affected  with  streptococcus  inflammation  of  the  udder 
is  believed  to  be  capable  of  causing  the  disease  in  human 
beings  who  use  it. 

The  angina  of  scarlet  fever,  when  uncomplicated  by  dipn- 
theria,  is  caused  by  the  ordinary  streptococcus  pyogenes ;  at 
least  this  pathogenic  species  is  so  constantly  present  in  the 
condition,  and  in  such  numbers  and  often  unassociated  with 
other  disease-producing  bacteria,  that  this  opinion  is  reason- 
ably justifiable. 

Diphtheria  may  be  engrafted  upon  scarlatina,  in  which 
event  bacilhis  dipJitJicrice  is  found  in  the  fauces,  usually  asso- 
ciated with  streptococci. 

The  angina  of  uncomplicated  scarlatina  is  not,  therefore, 
etiologically  identical  with  the  pseudomembranous  inflamma- 
tion of  the  fauces  that  characterizes  true  diphtheria,  though 
both  clinically  and  anatomically  it  may  present  a  number  of 
features  in  common  with  it. 

Prophylaxis. — The  patient  should  be  isolated  in  a  room 
as  scantily  and  simply  furnished  as  circumstances  will  permit. 
The  accompanying  diagram  illustrates  what  has  been  done 
in  Michigan  by  enforced  isolation  of  cases  of  both  scarlatina 
and  diphtheria  (Chart  15). 

Because  of  the  ease  with  which  the  disease  may  be  car- 
ried, only  the  physician,  nurse,  or  immediate  attendant  should 
have  access  to  the  room  ;  and  because  of  the  tenacity  to  life 
possessed  by  the  scarlatina  virus,  great  care  should  be  given 
to  the  disinfection  (by  boiling  water,  carbolic-acid  solution  or 
chlorid-of-lime  solution)  of  all  articles  before  they  are  per- 
mitted  to    leave  the  room. 

The  entire  surface  of  the  body  of  the  patient  should  be 
kept  anointed  with  an  antiseptic  oil  or  ointment  to  prevent 
the  escape  of  particles  of  epidermis  into  the  air.     The.se  pre- 


SCARLET  FEVER. 


185 


Chart  15. — Showing  influence  of  isolation  and  disinfection  upon  scar- 
latina and  diphtheria  in  Alichigan  during  the  eight  years  i88j  to 
1894. 


SCARLATINA 

DIPHTHERIA 

0 

eglected 
in  738 
utbreaks 
Average 

Enforced      ? 
in  412 
Outbreaks     0 
Averajte 

eglected 

in  467 

utbreaks 

Average 

Enforced 

in  310 

Outbreaks 

Average 

Ca 

ses  Deaths 

Cases 

Deaths  C 

ises  Deaths 

Cases 

Deaths 

14 

14 

U3-_ 
_12._ 
_U__ 
_L0._ 

_8__ 

_6__ 
_5__ 

_3-- 

_2_. 
1 

13 

1. 

>.04 

13 

1?! 

10 

9 

8 

fi 

5 

■t 

2.78— 

J 

2.09 

■ 

■ 

1 

1       IP^I 

II        II        1 

From  Report  cf  the  Michigan  State  Board  of  Health,  1897. 


1 86  HYGIENE    OF  TRANSMISSIBLE   DISEASES. 

cautions  should  be  observ^ed  until  desquamation  is  complete. 
After  removal  of  the  patient  the  room  should  be  carefully 
disinfected  with  formaldehyde  gas  and  the  bedding  subse- 
quenth'  subjected  to  steam  sterilization,  or  the  entire  wall- 
surfaces,  including  ceiling  and  floor,  all  furniture,  mantles, 
etc.,  should  be  thoroughly  wiped  with  a  cloth  or  sponge 
soaked  in  a  3  per  cent,  carbolic-acid  or  i  :  1000  corrosive- 
sublimate  solution ;  the  carpets,  hangings  (if  such  are 
present),  the  bed-clothing,  mattress,  etc.,  should  be  disin- 
fected by  steam.  These  should  be  enveloped  in  sheets 
soaked  in  either  of  the  above  solutions  before  being  taken 
from  the  room  to  the  disinfecting  station. 

The  bedstead  and  room  should  then  be  scrubbed  with 
soap  and  water,  the  windows  opened,  the  door  locked,  and 
the  room  thoroughly  aired  for  several  days. 


WHOOPING  COUGH. 

( Pertussis. ) 

Definition,  Cause,  etc. — A  contagious  disease  charac- 
terized by  a  peculiar  spasmodic  cough  that  ends  with  a 
"  whoop  "  (inspiratory)  from  which  the  disea.se  gets  its  desig- 
nation. 

The  investigations  that  have  been  made  upon  whooping 
cough  with  the  hope  of  discovering  its  cause  have  been  dis- 
cordant in  their  results.  Protozoa,  diplococci,  and  bacilli 
have  from  time  to  time  been  found  microscopically  and  been 
isolated  by  bacteriological  methods  from  cases  of  this  disease 
by  different  observers.  It  is  impossible  to  state  definitely 
which,  if  any,  of  the.se  several  micro-organisms  plays  the 
etiological  role  in  the  di.sease  ;  for  by  the  employment  of 
none  of  them  has  it  been  possible  to  reproduce  the  disea.se,  as 
it  is  seen  in  man,  in  lower  animals.  The  most  recent,  and 
in  many  ways  the  most  satisfactory,  of  these  .studies  is  that 


WHOOPING    COUGH.  1 87 

of  Koplic/  who  detected  in  13  out  of  a  series  of  16  cases  a 
bacillus,  which  he  thinks  may  reasonably  be  regarded  as 
playing  an  important  part  in  the  causation  of  the  disease.  In 
the  uncomplicated  cases  this  bacillus  was  often  the  only 
organism  present.  It  was  readily  isolated  in  pure  culture 
through  the  employment  of  coagulated  hydrocele  fluid  under 
anaerobic  conditions.  Inoculations  of  animals  with  this 
micro-organism  resulted  usually  in  local  or  general  suppura- 
tive infections,  and  in  no  instances  did  he  succeed  in  getting 
a  condition  that  in  any  way  suggested  the  disease  as  it 
occurred  in  man. 

Koplic  considers  it  as  reasonably  certain  that  the  organism 
found  by  him  is  identical  with  that  found  and  described  by 
Afanassjew  in   1887. 

"  Probably  the  lungs  are  the  seat  of  invasion,  and  the 
catarrhal  stage  represents  the  period  of  growth  of  the  micro- 
organism, the  paroxysmal  attacks  being  caused  by  the 
absorbed  toxins,  and  being  comparable  to  the  convulsions  of 
tetanus  "  (Goodall  and  Washbourn).  It  is  seen  both  sporad- 
ically and  as  outbreaks  of  varying  extent. 

It  is  a  disease  of  childhood,  though  no  age  is  exempt  from 
it.  It  is  more  frequent,  and  also  more  serious,  in  cold  than 
in  warm  climates.  According  to  the  statistics  of  Hirsch,  the 
season  of  the  year  seems  to  be  of  little  influence  upon  the 
prevalence,  though  it  is  usually  considered,  in  this  latitude,  to 
be  a  disease  of  winter  and  spring. 

The  fatality  of  this  disease  varies  considerably  in  different 
epidemics,  and  depends  largely  upon  the  secondary  compli- 
cations. It  is  much  more  fatal  in  negroes  than  in  white  chil- 
dren, and  in  females  than  in  males.  It  is  a  serious  malady, 
and  in  England  ranks  next  to  diarrhea  as  the  cause  of  mor- 
tality among  young  children,  though  the  last  United  States 
census  shows  it  to  be  hardly  so  fatal  in  this  country.  A 
single  attack  protects  against  recurrence  of  the  disease  in  the 
majority  of  cases. 

The  disease  is  disseminated  directly  from  the  sick  to  the 
well  individual  through  the  breath  and  through  matters  ex- 

^  CenU-albl.  fur  Bakteriologie  und  Parasitenkuttde,  1897,  Bd.  xxii.,  S.  222. 


1 88  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

truded  while  coughing,  though  there  is  reason  to  beHeve  that 
its  x'irus  ma)'  be  harbored  about  rooms,  in  clothing,  and  upon 
furniture.  It  is  contagious  from  the  onset  until  the  "  whoop  " 
has  disappeared. 

Prophylaxis. — The  serious  nature  of  whooping  cough, 
especially  when  occurring  in  very  young  and  feeble  children, 
calls  for  more  attention  to  the  prevention  of  its  spread  than 
it  ordinarily  gets. 

The  patient  should  be  carefully  isolated  for  as  long  as  the 
paroxysmal  cough  exists,  for  during  this  entire  period  they 
are  capable  of  disseminating  the  disease.  It  is  hardly  neces- 
sar}^,  therefore,  to  state  that  children  with  whooping  cough 
should  never  be  permitted  to  attend  school.  All  handker- 
chiefs, towels,  napkins,  eating-utensils,  etc.,  used  by  the  pa- 
tient should  be  disinfected  before  being  taken  from  the  apart- 
ment in  which  the  patient  is  isolated.  The  room  in  which 
the  patient  has  been  isolated  should  be  properly  disinfected 
after  it  has  been  vacated  ;  during  its  occupancy  all  horizontal 
surfaces  should  be  wiped  from  time  to  time  with  a  cloth 
moistened  in  a  3  per  cent,  carbolic-acid  solution.  When  the 
weather  permits,  the  patient  should  have  the  freest  possible 
access  to  fresh  air,  sunlight,  and  moderate  outdoor  exercise. 


MUMPS. 

Definition,  Cause,  etc. — An  acute,  specific  infection 
characterized  by  swelling  of  the  parotid  and  other  salivary 
glands.  Its  cause  is  not  as  yet  known.  Both  bacilli  and 
micrococci  hav^e  been  discovered  in  the  swollen  glands,  but 
they  are  not  shown  to  stand  in  causal  relation  to  the  disease. 

It  is  endemic  in  all  countries.  It  frequently  occurs  as  local 
epidemics.  It  is  most  prevalent  in  autumn  and  spring.  It 
occurs  between  the  ages  of  five  and  fifteen  years,  less  com- 
monly in   older  persons,  and  rarely  in   children  under  one 


MALARIAL   FEVER.  1 89 

year.  It  is  somewhat  more  common  in  boys  than  in  girls. 
It  is  markedly  contagious  and  spreads  by  direct  contact.  The 
breath  and  secretions  from  the  mouth  seem  capable  of  caus- 
ing infection.  It  is  not  conspicuously  disseminated  through 
the  agency  of  persons  or  by  fomites. 

Its  period  of  incubation  is  reckoned  as  from  fourteen  to 
twenty-five  days.  The  patient  is  considered  infectious,  especi- 
ally infectious,  during  the  period  of  active  inflammation  of  the 
salivary  glands. 

These  patients  should  be  isolated  for  at  least  three  weeks 
from  the  onset  of  the  disease. 


MALARIAL  FEVER. 

Definition,  Cause,  etc. — The  term  malarial  fever  is 
used  generically  to  indicate  a  group  of  febrile  disorders  that  re- 
sult from  the  invasion  of  the  body  by  a  specific  micro-organism 
— VIZ.,  Plasmodium  malaricE — discovered  by  Laveran  in  1880. 
Malarial  fevers  are  therefore  infectious,  though  they  are  not 
contagious. 

These  fevers  may  be  divided  clinically  into  two  primary 
groups — viz.,  the  intermittent  and  the  remittent  or  continued 
fevers,  though  etiologically  they  are  all  dependent  upon  the 
same  or  closely  allied  parasites. 

The  intermittent  malarial  fevers  are  characterized  by  the 
periodic  occurrence  or  paroxysms,  consisting  of  chills,  fever, 
and  sweating,  in  the  order  named,  and  by  the  disappearance 
of  symptoms  during  the  interval  between  the  paroxysms. 
According  to  the  length,  in  days,  of  the  interval  between 
paroxysms,  the  commoner  manifestations  of  the  intermittent 
fevers  are  designated  as  quotidian — /.  t\,  those  occurring  every 
day ;  tertian,  occurring  ever>'  other  day ;  quartan,  occurring 
after  an  interval  of  two  days. 

In  the  remittent  or  continued  types  of  the  fever  the  char- 
acteristic, periodic  occurrence  is  often  lost.     The  fever  may 


190 


HYGIENE    OF  TRANSMISSIBLE  DISEASES. 


be  continuously  above  normal,  and  there  may  be  regular  or 
irregular  remissions. 

Pernicious  malarial  fever  is  a  rare  manifestation  of  the  dis- 
ease in  this  latitude.  It  represents  a  condition  in  which  the 
body  is  more  or  less  suddenly  overwhelmed  by  the  malarial 
poison.  It  is  often  fatal.  Three  clinical  forms  of  pernicious 
malarial  fever  are  recognizable — viz.,  the  comatose,  in  which 
the  symptoms  are  principally  cerebral ;  the  hemorrhagic, 
characterized  by  hemorrhage  from  the  mucous  membranes 
and  from  the  kidneys ;  and  the  algid  form,  in  which  the  most 
conspicuous  symptom  is  extreme  prostration,  with  little  or 
no  tendency  to  rise  in  temperature.  The  true  nature  of 
these  symptoms  is  frequently  difficult  of  recognition  by  the 


g)@@@(g)@(g) 
@@®©@@ 

^^  /«  /r  /^ 

®@@®@@(g) 

/^    J^     J^      J^  '^  ^^ 


22  ^J 


Fig.  22. — Diagrammatic  representation  of  the  succession  of  shapes  assumed 
by  an  actively  amoeboid  intracorpuscular  plasmodium  during  the  course  of  five 
minutes  (author's  observations). 

ordinary  clinical  procedures.  This  difficulty  is,  however, 
easily  cleared  away  by  microscopical  examination  of  the 
blood  for  the  causative  parasite. 

The  Plasmodium  of  malaria  is  an  animal  parasite  belonging 
to  the  protozoa — /.  c,  it  con.sists  of  simple,  undifferentiated 
protoplasm.  Because  of  its  presence  in  the  blood  it  is  often 
referred  to  as  "  hematozoon."  In  tlie  blood  of  persons  suffer- 
ing from  the  .same  type  and  in  the  blood  of  those  suffering 


MALARIAL    FEVER.  I9I 

from  different  types  of  malarial  fever,  a  number  of  different 
forms  or  developmental  phases  of  the  parasite  may  be 
observed. 

It  is  hardly  appropriate  in  a  sketch  of  this  character  to 
describe  in  detail  all  the  various  forms  that  are  assumed  by 
the  Plasmodium  of  malaria,  or  to  enter  into  a  full  description 
of  the  developmental  steps  through  which  it  passes  in  the 
several  forms  of  fever  in  which  its  life  history  has  been  care- 
fully studied.  It  will  suffice,  for  purposes  of  illustration,  to 
follow  here  the  development  of  the  parasite  in  one  of  the 
typical  clinical  manifestations  of  intermittent  fever,  and  to 
refer  the  reader  to  special  monographs  for  full  details  of  the 
subject.^  The  commonest  of  the  intermittent  fevers  encoun- 
tered in  this  vicinity  is  the  tertian  type — i.  c,  that  in  which  the 
paroxysms  occur  on  each  alternate  day. 

If  one  examine  the  fresh  unstained  blood  of  a  patient  suf- 
fering from  tertian  intermittent  fever,  during  the  latter  part  of 
or  shortly  after  the  paroxysm,  one  will  observe  that  many  of 
the  red  blood-corpuscles  contain  within  them  small,  round, 
pale  bodies  that  occupy  from  about  a  sixth  to  a  fifth  of  the 
corpuscle  in  which  they  are  located  (i  in  Fig.  23).  They 
are  actively  amoeboid  and,  as  a  result,  the  pseudopedia  that 
they  are  constantly  throwing  out,  cause  them  to  assume  a 
variety  of  shapes  that  follow  upon  one  another  in  quick 
succession  (see  2,  3,  4,  5,  Fig.  23).  As  time  passes  on,  these 
small  bodies  increase  in  size  ;  gradually  reddish-brown  pig- 
ment-granules begin  to  appear  within  them.  These  are  at 
first  very  minute.  They  vary  in  shape,  and  are  in  active, 
oscillating  motion.  The  organism  gradually  increases  in 
size,  and  the  pigment  becomes  more  manifest.  The  cor- 
puscle in  which  the  organism  is  located  becomes  paler,  and, 
when  compared  with  its  normal  neighbors,  is  seen  to  have 
appreciably  increased  in  size.     With  further  growth  of  the 

'  The  most  complete  and  satisfactory  treatment  of  this  subject  that  it  has 
been  my  good  fortune  to  encounter  is  contained  in  "  The  Malarial  Fevers  of 
Baltimore,  etc.,"  by  Thayer  and  Yiewetson,  Johns  Hopkins  Hospital  Reports, 
1895,  vol.  V.  See  also — Lectures  on  the  Malarial  Fevers — by  Wm.  Sidney 
Thayer,  M.  D.,  published  by  Appleton  &  Co.,  N.  Y.,  1897. 


192 


HYGIEXE    OF   TRANSMISSIBLE  DISEASES. 


organism  its  amoeboid  movement  becomes  less  apparent. 
The  amount  of  pigment  increases ;  it  continues  its  active 
dancing  motion,  and  is  now  seen  to  be  irregularly  arranged 
around  the  periphery  of  the  organism  (6  in  Fig.  23).  Before 
the  end  of  forty-eight  hours  the  organism  has  usually  com- 
pletely filled  its  enveloping  red  blood-corpuscle.  The  pig- 
ment is  very  much  increased  in  amount,  and  surrounding 
the  organism  is  a  thin  rim,  the  remains  of  the  invaded  cor- 
puscle. Sometimes  all  indication  of  red  corpuscle  disappears. 
When  this  stage  is  reached,  the  hitherto  actively  oscillating 
pigment  becomes  motionless,  or  nearly  so,  and  tends  to  col- 
lect near  the  center  either  as  a  single  black  or  as  a  mass  of 


Fig.  23. — Some  of  the   principal  forms  assumed  by  the   plasmodium   of  tertian 
fever  in  the  course  of  its  cycle  of  development  (after  Thayer  and  Hewetson). 

dark,  almost  black  granules.  The  substance  of  the  organism 
now  becomes  finely  granular  and  somewhat  more  refractive. 
Indistinct  radial  striations  make  their  appearance  at  the 
periphery  of  the  body ;  these  grow  more  and  more  distinct, 
till  finally  the  central  pigment-mass  is  surrounded  by  from 
12  to  20  or  more  pear-shaped  segments  that  give  to  the 
whole  a  rosette-like  appearance  (7,  8,  9,  10  in  Fig.  23).  Each 
segment  presents  a  small  refractive  central  spot.  A  little 
later  the  central  pigment-clump  is  seen  to  be  surrounded  by 
a  group  of  completely  separated,  round,  hyaline  bodies  simi- 
lar in  all  respects  to  those  seen  in  the  corpuscles  at  the 
beginning  of  the  observation  (11  in  Fig.  23) — i.  c,  during  the 
latter  part  of,  or  shortly  after,  the  preceding  paroxysm  ;  at 


MALARIAL    FEVER.  1 93 

this  time  also  one  begins  to  notice  the  appearance  of  similar, 
small,  hyaline  bodies  in  some  of  the  red  corpuscles.  "  We 
have  thus  a  very  suggestive  chain  of  evidence  in  favor  of  the 
view  that  this  is  a  reproductive  process ;  that  these  hyaline 
segments  resulting  from  the  division  of  the  organism  are 
identical  with  the  fresh  hyaline  forms  that  appear  in  the  red 
cells."  ^  It  is  highly  probable  that  these  segments  represent 
a  brood  of  young  parasites  which,  in  time,  invade  a  fresh  set 
of  corpuscles  and  undergo  the  cycle  of  development  and 
reproduction  described  for  their  progenitors.  The  final  de- 
velopmental phase  of  the  parasite — viz.,  segmentation — is 
always  coincident  with  or  a  little  antecedent  to  the  occurrence 
of  a  characteristic  paroxysm. 

Based  upon  these  observations  Golgi  formulated  the  fol- 
lowing laws :  "  Each  febrile  paroxysm  is  closely  connected 
with  the  cycle  of  development  of  a  generation  of  parasites : 
the  beginning  of  each  paroxysm  corresponds  to  the  matura- 
tion of  a  generation  of  parasites  :  the  severity  of  the  paroxysm 
is,  in  general,  proportional  to  the  number  of  the  parasites 
which  are  found  in  the  blood." 

Opinion  as  to  the  actual  cause  of  the  characteristic  parox- 
ysm is  divided.  Golgi  believes  it  to  be  due  to  the  invasion 
of  the  red  blood-corpuscles  by  the  brood  of  young  parasites 
that  have  resulted  from  the  segmentation  of  the  mature  or- 
ganism, while  Antolisei  considers  the  chill  to  be  due  to  the 
actual  segmentation  of  the  fully-grown  plasmodia,  rather  than 
to  the  invasion  of  the  corpuscles.  Baccelli  suggests  the  toxic 
origin  of  the  paroxysm,  and  advances  the  idea  (now  accept- 
able to  the  majority  of  investigators)  that  the  phenomenon 
results  from  the  influence  upon  the  vasomotor  centers  of  a 
poison,  either  liberated  at  the  time  of  segmentation  by  the 
parasite  or  occurring  as  a  product  from  the  red  blood-corpus- 
cles that  have  been  destroyed. 

In  addition  to  the  small  and  large  amceboid  and  pigmented 
forms  that  are  regularly  observed  in  the  developmental  cycle 
of  the  parasite,  in  tertian,  quartan,  and  aestivo-autumnal  fevers, 
other  forms  are  encountered.    The  most  conspicuous  of  these 

1  The  above  description  is  condensed  from  Thayer  and  Hewetson,  loc.  cit. 
13 


194 


HYGIENE    OF  TJ^ANSMISSIBLE  DISEASES. 


are  the  flagellated  varieties  and  the  "  crescents  "  (Fig.  24). 
The  former  are  seen  in  one  or  all  varieties  of  intermittent 
fever,  usually  at  or  about  the  period  of  the  paroxysm ;  and 
in  the  aestivo-autumnal  fever  Thayer  and  Hewetson  frequently 
detected  them  in  the  blood-specimens  long  after  all  febrile 
symptoms  had  disappeared.  They  are  easily  recognized, 
consisting  of  a  pale,  pigmented  body  often  as  large  as,  some- 
times larger  (according  to  circumstances)  than  a  red  corpus- 
cle, which  is  provided  with  one  or  more  slender,  thread-like 
flagella  that  lash  about  in  a  very  active  manner.     One  or 


Fig.  24. — Crescentic  and  flagellated  forms  of  Plasmodium  malariae :  i,  flagel- 
lated form  of  tertian  fever;  2,  flagellated  form  of  quartan  fever;  3,  crescents,  and 
4,  flagellated  form  of  gestivo-autumnal  fever  (after  Thayer  and  Hewetson). 


more  flagella  may  become  detached  and  lead  an  independent 
existence.  The  pigment-granules  contained  within  the  body 
are  in  active  dancing  motion,  and  an  amoeboid  movement  of 
the  body  can  usually  be  made  out.  For  reasons  too  numer- 
ous to  discuss  here,  the  flagellated  forms  are  regarded  by 
many  to  be  degenerative  forms  of  the  parasite,  while,  on  the 
other  hand,  others  consider  them  to  represent  the  organism 
in  its  highest  stage  of  development. 

In  his  paper  "  On  the  Hematozoon  Infection  of  Birds,"  ' 
MacCallum  describes  an  observation  of  fundamental  impor- 
tance that  he  has  made  upon  the  developing  parasites  in  the 
blood  of  crows.     He  has  ob.served  that  in  a  particular  stage 

^  Jour,  vf  Experimental  Medicine,  1898,  vol.  ill.,  p.   117. 


MALARIAL    FEVER.  1 95 

of  development  two  forms  of  the  organism  may  be  simulta- 
neously encountered  : — one  a  motionless  pigmented,  the  other 
a  hyaline,  actively  motile,  flagellated  body.  After  a  time  the 
flagella  become  detached  from  the  latter  and  one  of  them  may 
readily  be  seen  to  penetrate  the  motionless  granular  form, 
while  the  remaining  flagella  from  the  same  parent  organism 
disappear.  He  regards  this  as  a  sexual  phenomenon  and 
suggests  the  probability  of  the  flagellated  malarial  parasite 
of  man  having  a  similar  significance. 

The  "  crescents,"  as  their  name  implies,  are  crescentic  in 
shape.  They  are  somewhat  refractive  bodies  that  are  usually 
marked  about  the  center  with  an  irregular  clump  or  ring  of 
pigment-granules.  They  may  lie  free,  or  have  attached  to 
them  what  appears  to  be  the  remains  of  a  red  blood-cor- 
puscle. They  are  encountered  only  in  the  protracted  forms 
of  malarial  poisoning — /.  e.,  after  the  second  week  in  the 
aestivo-autumnal  fever,  in  the  malarial  remittent  fevers,  and 
in  the  cachectic  victims  of  chronic  malaria.  Their  significance 
is  not  definitely  understood. 

In  the  present  state  of  our  knowledge  it  is  difficult  to 
decide  whether  all  the  various  forms  of  the  parasite,  as  seen 
in  the  blood  in  the  different  expressions  of  malarial  infection, 
represent  developmental  stages  of  one  and  the  same  poly- 
morphic organism,  or  whether  some  of  them  are  phases  of 
one  and  others  of  another  variety,  or  of  other  varieties,  of  the 
closely-allied  species  of  protozoa  that  are  all  capable  of  in- 
ducing symptoms  characteristic  of  malarial  fever.  Certain 
it  is,  however,  that  among  the  most  competent  students  of 
these  fevers  there  is  practically  an  agreement  of  opinion  that 
at  least  three  distinct  varieties  of  the  parasite  are  concerned 
in  producing  the  three  commonest  manifestations  of  malarial 
infection — viz.,  the  tertian,  the  quartan,  and  the  aestivo- 
autumnal  fevers — and  that  during  the  course  of  these  fevers 
it  is  possible  to  detect  a  pretty  regular  series  of  develop- 
mental phases  through  which  each  of  the  varieties  of  the 
parasite  passes,  beginning  with  the  small,  simple,  intra- 
corpuscular  body,  and  ending  with  one  mode  of  segmenta- 
tion (reproduction)  or  another.     The  parasite  has  not  been 


196  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

observed  outside  the  body,  and  we  have  not  as  yet  sufficient 
data  on  wliich  to  base  a  positive  statement  as  to  all  the  portals 
through  which  it  gains  entrance  to  the  body. 

Geographical  Distribution. — The  malarial  fevers  have 
a  very  wide  distribution.  They  vary  markedly  in  the  degree 
of  their  intensity  in  different  localities. 

It  may  in  general  be  said  that  the  most  severe  manifesta- 
tions are  seen  in  tropical  countries ;  and  that  as  we  pass  from 
these  regions  of  greatest  malignancy  into  the  temperate  zones, 
the  centers  of  endemicity  become  less  frequent  and  the  char- 
acter of  the  disease  less  virulent. 

The  disease  is  seen  in  its  greatest  severity  upon  the  west 
coast  of  Africa  ;  in  Algeria  ;  along  the  coasts  of  India,  China, 
and  Persia ;  in  Chili,  Peru,  and  Brazil ;  on  the  eastern  coasts 
of  Central  America  and  Mexico  ;  and  along  the  shores  of 
the  southern  United  States  that  border  upon  the  Gulf  of 
Mexico. 

The  principal  malarial  regions  of  Europe  are  southern 
Russia  in  the  region  of  the  Caspian  Sea ;  southern  Germany 
along  the  lower  Rhine  and  Danube  ;  the  west  coast  and  a 
large  part  of  northern  Italy ;  southeastern  France,  especially 
in  the  valleys  of  the  Loire  and  Rhone ;  and  the  southwest 
coast  of  Portugal. 

In  isolated  areas  the  disease  is  seen  in  northern,  north- 
western, and  western  Europe,  though  to  a  much  less  extent 
than  in  the  other  localities  named.  It  is  rare  in  England, 
prevailing  to  only  a  limited  degree  near  the  east  coast. 

In  this  countiy  the  disease  is  much  more  frequent,  and  its 
manifestations  are  much  more  severe  in  parts  of  the  southern 
and  southwestern  States  than  elsewhere.  In  the  Middle 
States  there  are  a  number  of  endemic  centers,  while  as  we 
pass  into  the  northern  and  New  England  States  these 
become  much  reduced  in  number.  In  the  northwestern 
States  and  in  northwestern  Canada  the  disease  is  almost 
unknown.  In  late  years  both  the  frequency  and  the  severity 
of  malaria  in  this  latitude  have  undergone  a  veiy  great  modi- 
fication, and  many  localities  in  which  the  disea.se  was  formerly 
endemic  have  become  practically  free  from  it. 


MALARIAL   FEVER.  I97 

The  remittent  and  pernicious  forms  of  malaria  are  most 
frequently  encountered  in  tropical  and  subtropical  regions. 
The  intermittent  fevers,  especially  the  quotidian  and  the 
quartan,  while  also  common  in  the  warmer  localities,  are 
widespread  in  their  distribution,  being  frequently  encoun- 
tered in  temperate  latitudes.  The  commonest,  and  at  the 
same  time  the  least  malignant,  form  of  malarial  fever  that 
ordinarily  prevails  in  the  higher  latitudes,  is  the  tertian 
remittent  fever. 

Conditions  that  Influence  the  Development  of  the 
Malarial  Virus. — The  designations  "  paludism,"  "  paludial," 
and  "  marsh  fever,"  by  which  malarial  fever  is  variously 
known,  indicate  the  close  relation  that  it  is  believed  to  have 
to  marshy  and  swampy  localities. 

Notwithstanding  the  fact  that  malaria  is  known  to  occur  in 
localities  that  are  not  marshy,  and  on  the  other  hand  to  be 
often  absent  from  those  that  are  low-lying  and  swampy,  it 
must  be  admitted  that  it  is  much  more  frequent  and  severe  in 
partly  inundated,  badly  drained  lands  than  in  localities  of 
higher  altitude,  where  the  drainage  of  the  soil  is  more  com- 
plete. 

A  certain  amount  of  water  in  the  soil  appears  to  be  an  es- 
sential for  the  development  of  the  malarial  virus. 

Marshes  that  are  alternately  flooded  and  imperfectly 
drained  of  water  offer  conditions  that  are  most  favorable  to 
the  occurrence  of  malaria.  A  malarious  marsh  if  completely 
and  permanently  flooded  may  become  innocuous  ;  but  it  will 
usually  resume  its  dangerous  character  if  the  water-level  is 
permitted  to  fall  sufficiently  low  to  expose  its  earthy  surface. 

Many  marshes  that  are  periodically  flooded  by  salt  water 
are  the  breeding-grounds  of  the  most  malignant  forms  of  ma- 
larial poisons,  while  others,  even  when  located  in  the  tropics, 
are  free  from  such  danger. 

It  is  a  notorious  fact  that  malarious  swamps  may  be,  and 
often  have  been,  robbed  of  their  noxious  qualities  by  proper 
drainage.  Where  adequate  arrangements  for  drainage  have 
not  been  provided,  malaria  has  been  known  to  follow  upon 
the  artificial  irrigation  of  arid  lands. 


198  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

The  soil  conditions  that  are  regarded  as  especially  favora- 
ble to  the  development  of  malaria  are  excess  of  moisture  and 
of  decaying  vegetable  matters,  such  as  obtain  in  low-lying, 
marshy  places,  in  the  broad  alluvial  deltas  of  great  rivers,  and 
along  the  valleys  of  smaller  steams,  particularly  where  these 
are  located  in  the  warmer  latitudes. 

"  By  far  the  largest  proportion  of  cases  of  malarial  fevers 
originates,  not  from  exposure  to  the  air  of  marshes,  but  from 
the  malaria  given  off  from  damp  bottom  lands,  from  the  del- 
tas of  rivers  subject  to  annual  overflow,  from  the  margins  of 
streams  when  these  are  exposed  during  the  dry  season,  and 
especially  from  alluvial  plains  under  cultivation.  This  natur- 
ally results  from  the  necessary  exposure  in  these  situations, 
and  from  the  fact  that  malarious  marshes  are  avoided  as  far 
as  possible  "  (Sternberg). 

The  geological  condition,  pci'  sc,  of  a  soil  does  not  appear 
to  play  an  important  part  in  the  production  of  the  virus,  nor 
does  its  locality  seem  in  all  instances  to  be  an  essential  factor, 
for  the  disease  has  been  observed  in  elevated  mountainous 
districts  and  in  low-lying  sandy  plains. 

Throughout  the  malarious  zones  it  has  generally  been  ob- 
served that  the  breaking  up  of  virgin  lands  has,  as  a  rule,  re- 
sulted in  the  appearance  of  malaria  in  the  immediate  vicinity, 
and  that  often  by  prolonged  cultivation  of  such  soils  the  dis- 
ease ultimately  becomes  less  frequent  and  severe,  and  may 
finally  disappear  altogether  from  the  neighborhood. 

While  the  above-mentioned  conditions  of  the  soil  are  in  the 
main  those  usually  regarded  as  most  favorable  to  the  exist- 
ence of  malaria,  .still  they  are  not  infallible  indications.  In  fact, 
one  cannot  certainly  predict  from  physical  conditions  alone 
whether  this  or  that  locality  is  healthy  or  not  as  regards 
malarial  fever.  On  this  point  Osier  expres.ses  the  opinion 
that  the  only  safe  guide  is  the  existence  of  the  disease  among 
people  residing  in  the  immediate  vicinity. 

The  influence  of  rainfall  depends  upon  circumstances.  If 
by  an  excess  of  rainfall  the  low-lying  malarious  lands  be- 
come completely  flooded,  the  disease  may,  in  consequence,  be 
temporarily  arrested.     An  impervious  surface-soil  that  does 


MALARIAL   FEVER.  I99 

not  readily  become  saturated,  but  rather  favors  the  rapid 
shedding  of  rain-water,  is  not  regarded  as  favorable  to  the  de- 
velopment of  the  disease.  A  permeable,  shallow  surface-soil 
overlying  an  impervious  stratum  may  favor  the  growth  of  the 
virus  under  the  conditions  of  very  moderate  rainfall. 

As  a  rule,  diy,  porous,  sandy  or  gravelly  soils  are  less  fre- 
quently favorable  to  malaria  than  those  that  more  readily  re- 
tain moisture  and  are  constantly  partly  saturated  with  water. 

Influence  of  Season. — In  this  latitude  malaria  appears 
most  conspicuously  in  spring  and  autumn,  and  least  of  all  in 
winter — /.  c,  it  occurs  in  those  seasons  that  are  characterized 
on  one  hand  by  beginning  growth  of  vegetation,  and  on  the 
other  by  its  death  and  decay. 

A  moderately  high  temperature  appears  to  be  an  essential 
factor  to  the  development  of  the  malarial  virus.  In  both 
tropical  and  temperate  regions  the  fever  is  more  prevalent 
after  prolonged  hot  spells.  According  to  Wood  and  to 
Drake,  malaria  is  rarely  developed  at  a  temperature  lower 
than  60°   F. 

As  a  rule,  it  becomes  less  frequent  and  less  malignant  as 
we  recede  from  the  thermal  conditions  that  obtain  in  the 
tropics  to  those  of  higher  latitudes. 

Influence  of  Air=currents. — There  is  a  widespread  convic- 
tion that  the  malarious  virus  may  be  carried  by  winds.  In 
malarious  regions  near  the  coast  the  land-breezes,  especially 
if  they  traverse  neighboring  marshes,  are  poisonous,  while  the 
sea-breezes  are  not.  Many  localities  that  may  be  otherwise 
highly  suspicious,  but  which  are  continuously  wind-swept,  are 
often  free  from  the  disease.  This  is  especially  true  for  many 
of  the  tropical  islands  of  the  Gulf  of  Mexico  and  the  Pacific 
Ocean. 

Under  ordinary  circumstances,  the  virus  of  malaria  is  not 
believed  to  ascend  very  high  above  the  ground.  In  malarious 
districts  it  is  a  common  observation  that  the  dwellers  in  high 
places,  in  the  upper  stories  of  houses,  etc.,  may  escape  the 
disease,  while  those  on  the  ground-floor  contract  it. 

When  regularly  seen  in  places  of  high  altitude  it  is  not 
usually  due  to  its  ascent  with   currents  of  air  from  the  low 


2CK)  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

lands,  but  rather  to  its  development  under  local  conditions 
that  may  exist  at  the  high  level.  There  is,  however,  evidence 
to  indicate  the  possibility  of  its  being  wafted  to  high  altitudes 
by  ver}'  strong  winds  blowing  along  narrow,  insalubrious  val- 
leys and  up  mountain  sides. 

Modes  and  Portals  of  Infection. — Since  the  malarial 
parasite  has  not  been  observed  outside  the  body,  it  is  impos- 
sible to  speak  with  certainty  as  to  all  the  modes  of  its  entiy 
into  the  system. 

The  ideas  hitherto  held  with  regard  to  this  point  are  that 
infection  may  occur  through  the  alimentary  and  respiratory 
tracts,  and  through  small  wounds  of  the  skin,  such,  for 
instance,  as  those  resulting  from  the  bites  of  insects,  espe- 
cially mosquitoes.  Though  these  views  are  based  upon  what 
are  believed  to  be  pretty  trustworthy  observations,  still,  in 
the  light  of  experiment,  they  appear  to  be  of  very  different 
degrees  of  importance.  As  a  result  of  modern  investigations 
it  seems  probable  that,  of  the  three  portals  mentioned,  skin- 
wounds  made  by  insects  are  the  most  frequent  and  the 
alimentar}^  tract  the  least  frequent  channels  through  which 
the  organism  gains   access  to  the  blood. 

The  investigations  of  a  number  of  the  Italian  observers 
(Celli,  Marino,  Zeri,  Grassi,  and  Feletti)  demonstrate  that  it 
is  practically  impossible  to  cause  malarial  infection  by  way 
of  the  alimentary  tract.  In  these  experiments  healthy  per- 
sons were  permitted  to  drink  of  water  from  malarious 
marshes ;  enemata  of  similar  waters  were  given  to  other 
persons ;  and,  in  the  experiments  of  Grassi  and  Feletti, 
healthy  persons  were  allowed  to  drink  of  blood  from  malarial 
patients,  but  in  no  instance  did  malaria  result.  We  feel 
justified,  therefore,  in  concluding  that  either  this  is  a  very 
unusual  mode  of  infection,  or  that  some  important  factor 
that  is  present  in  the  course  of  natural  infection  was  inad- 
vertently omitted  from  the  experiments. 

There  is  a  ver}'  general  impression  that  infection  can  occur 
through  the  respiratory  tract,  though  as  yet  we  have  no 
proof  of  it,  and  the  results  of  experiment  leave  the  question 
still  in  a  very  unsatisfactory  state. 


MALARIAL    FEVER.  20I 

With  regard  to  infection  through  wounds  of  the  skin, 
Bignami '  holds  the  opinion  that  this  is  the  most  frequent 
channel  throug-h  which  the  disease  is  contracted,  and  he 
advances  very  strong  arguments  in  support  of  the  view  that 
infection  is  usually  due  to  the  bites  of  mosquitoes,  much  in 
the  same  way  that  the  Texas  fever  of  cattle  originates  with 
and  is  disseminated  by  the  bites  of  infected  ticks.  Among 
many  forcible  arguments  in  support  of  his  hypothesis,  Big- 
nami states  that  in  the  highly  malarious  regions  of  Italy 
the  precautions  taken  by  the  natives  against  malarial  fever 
are  always  equally  effective  against  mosquitoes.  These  indi- 
viduals in  some  localities  sleep  in  houses  elevated  upon 
stakes  or  piles  to  a  distance  of  12  to  15  feet  above  the 
ground.  They  avoid  going  out  at  night.  They  are  careful 
not  to  sleep  in  the  open  air  at  any  time  day  or  night.  They 
close  their  windows  with  badly  fitting  shutters,  which  impede 
the  ingress  of  insects  but  not  of  air.  They  take  great  care 
of  their  mosquito  curtain,  making  it  of  very  close  net,  under 
which  they  sleep,  thoroughly  shut  in,  notwithstanding  the 
great  heat.  Bignami  ascribes  the  limited  vertical  ascent  of 
the  malarial  virus  in  the  air  to  the  fact  that  mosquitoes  as  a 
rule  do  not  fly  very  high  above  the  ground.  In  view  of  the 
fact  that  the  only  method  by  which  genuine  malaria  has  been 
produced  experimentally  in  man  is  that  of  inoculation  with 
the  blood  of  malarial  patients,  and  that  this  has  repeatedly 
been  done,  the  opinion  advanced  by  Bignami  acquires  con- 
siderable importance.  In  a  discussion  of  this  subject  Laveran 
also  expresses  the  belief  that  the  disease  is  much  more  often 
contracted  through  the  bites  of  insects,  particularly  mosqui- 
toes, than  in  any  other  way.^ 

The  whole  question,  however,  of  mode  of  infection  in 
malaria  is  as  yet  in  a  somewhat  unsatisfactory  state. 

Prophylaxis. — From  the  foregoing  the  measures  of  pre- 
vention may  readily  be  summarized  as  follows  : 

Efficient  drainage  of  damp  soils. 

^  "  Hypothesis  as  to  the  Life  History  of  the  Malarial  Parasite  outside  the 
Human  Body,"  Lancet,  Nov.  14  and  21,  1896. 

^  "Comment  prend — on  le  paludisme,"  Revue  d'' Hygiene,  1896,  p.  1049. 


202  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

Place  of  residence  as  high  above  and  as  far  removed  from 
low-lying  districts  as  circumstances  will  permit. 

Avoid  sleeping  in  the  open  air  in  malarious  districts  during 
either  the  day  or  night. 

Adequate  protection  against  the  bites  of  insects,  especially 
of  mosquitoes. 

Though  experimental  evidence  contra-indicates  its  neces- 
sit}',  both  food  and  water  should  be  cooked  in  malarious 
regions. 

While  in  malarious  regions  it  is  a  valuable  precaution  to 
take  from  4  to  5  grains  of  quinine  daily  on  rising  in  the 
morning. 

Note  i. — From  a  series  of  experiments,  the  results  of  whicli  have  been 
recently  published  i^Centralbl.  fiir  Baktei-iologie,  1897,  Bd.  xxi.,  S.  49),  Celli 
and  Santeri  draw  the  conclusion  that  the  period  of  incubation  of  malarial  in- 
fection may  be  very  much  prolonged  through  the  injection  into  the  individual 
of  the  blood-serum  from  certain  animals  that  are  naturally  immune  from  ma- 
laria. This  observation,  while  of  scientific  interest,  can  hardly  be  regarded 
as  of  very  great  practical  importance,  since  we  already  possess,  in  quinine,  a 
body  that,  in  both  its  therapeutic  and  prophylactic  employment,  is  known  to 
be  a  specific,  in  the  full  sense  of  the  word,  against  malaria. 

Note  2. — It  is  my  pleasant  duty  to  acknowledge  the  assistance  that  I  have 
received,  in  the  preparation  of  this  sketch,  from  the  exhaustive  monograph  of 
Thayer  and  Hewetson,  already  referred  to. 


YELLOW  FEVER. 


Definition. — An  acute,  specific,  febrile  disease  of  tropical 
and  subtropical  climates  that  is  characterized  by  jaundice, 
hemorrhages  from  the  mucous  membranes,  vomiting  of  dark 
or  black,  grumous  matters  (the  so-called  "  black  vomit  ")  and 
albuminuria.  It  occurs  endemically  in  certain  districts  of  the 
tropics,  and  at  times  spreads  epidemically  over  regions  be- 
yond the  zone  of  endemicity.  Though  its  cause  is  not  known, 
it  is  obviously  an  infectious  disease.  It  is  not  regarded  as  con- 
tagious— /.  c,  directly  transmissible  from  the  sick  to  the  well. 


YELLOW  FEVER. 


203 


Btiology. — Notwithstanding  the  fact  that  a  good  deal  has 
been  said  and  written  during  the  past  two  years  on  the  etiol- 
ogy of  this  disease,  there  are  still  good  grounds  for  believing 
that  the  exciting  cause  of  yellow  fever  has  not  yet  been  dis- 
covered. 

The  contributions  upon  the  subject  that  have  received  the 
most  serious  consideration  are  those  of  Sternberg  and  of 
Sanarelli. 

In  1888  Sternberg  called  attention  to  the  micro-organism, 
designated  by  him  as  "  bacillus  X"  that  he  had  found  in 
about  50  per  cent,  of  fresh  yellow-fever  cadavers  examined 
by  him.  He  did  not  certainly  regard  it  as  the  cause  of  the 
disease,  though,  because  of  its  pathogenic  properties  and  its 
presence  in  only  yellow  fever,  he  thought  it  might  possibly  be, 
in  some  way  or  other,  concerned  in  its  etiology. 

In  1897  Sanarelli  described  a  bacillus,  designated  by  him 
z.^ '^  bacillus  ictC7'oides','  that  he  had  discovered  in  about  58 
per  cent,  of  yellow-fever  cadavers  examined  by  him  at  Monte 
Video.  From  its  presence  in  only  yellow-fever  cadavers,  its 
pathogenesis,  and  the  peculiarity  of  the  lesions  produced  in 
animals  inoculated  with  it,  he  feels  justified  in  regarding  it  as 
the  specific  exciting  cause  of  yellow  fever.  He  claims  to 
have  rendered  animals  immune  from  the  disease  by  the  use 
of  his  cultures  of  this  bacillus,  and  he  further  states  that  the 
serum  obtained  from  such  immune  animals  has  the  property 
of  protecting  individuals  into  whom  it  may  be  injected  from 
yellow  fever.  A  comparison  of  the  descriptions  of  these  two 
organisms  leaves  little  doubt  that  they  are  closely  related, 
though  not  identical ;  that  they  can  reasonably  be  embraced 
within  the  colon  group  of  bacilli ;  and  that  the  results  of 
inoculations  of  animals  with  them  do  not,  in  the  majority  of 
cases,  materially  differ  from  those  obtained  occasionally 
through  the  injection  of  the  colon  bacillus  or  some  one  of 
its  varieties.^    As  a  result  of  these  facts,  the  opinion  expressed 

^  Reed  and  Carroll  {^Medical  News,  April  29,  1899)  have  subjected  '-'■  ba- 
cillus X"  and  ^'■bacillus  ideroides''''  to  exhaustive  study,  and  as  a  result  reach 
the  following  important  conclusion  :  "  We  venture  to  express  the  opinion  that 
bacillus  icteroides  (Sanarelli)  is  a  variety  of  the  hog-cholera  bacillus,  and  that 


204  HYGIENE    OE    TRANSMISSIBLE   DISEASES. 

by  Sanarelli  as  to  its  standing  in  causal  relation  to  yellow 
fever  has  not  met  with  general  acceptance  on  the  part  of 
bacteriologists. 

It  has  been  suggested,  or  rather  predicted,  that  if  the 
cause  of  this  disease  is  ever  discovered  it  will  be  found  to  be  a 
haematozoon,  zoologically  allied  to  the  malarial  parasite  of 
man,  but  on  this  point  there  is  as  yet  no  evidence  whatever. 

Geographical  Distribution. — According  to  Hirsch,  the 
geographical  limits  between  which  it  is  possible  for  yellow 
fever  to  occur  are  represented  in  the  western  hemisphere  by 
the  latitudes  34°  54'  south  (Monte  Video)  and  44°  39'  north 
(Halifax) ;  and  in  the  eastern  hemisphere  by  8°  45'  south 
(Ascension)  and  51°  37'  north  (Swansea).  Within  these 
boundaries  there  are  localities  from  which  the  disease  is  never 
absent ;  others  in  which  it  is  more  or  less  frequently  present, 
and  others  in  which  it  only  occasionally  occurs  as  a  result  of 
accidental  importation. 

The  three  principal  districts  in  which  yellow  fever  is  really 
endemic  are  the  West  Indies,  the  Mexican  part  of  the  Gulf 
coast,  and  the  Guinea  coast  at  Sierra  Leone.  The  latitude  of 
these  localities  is  regarded  by  Guiteras  as  comprising  the 
"  focal  zone  "  of  yellow  fever,  while  the  coast  of  tropical  At- 
lantic, both  in  America  and  in  Africa,  he  designates  as  the 
"  perifocal  "  zone,  or  the  regions  of  periodic  epidemics. 

Epidemics  of  this  disease  were  at  one  time  frequent  in  this 
country,  especially  during  the  last  and  the  early  part  of  the 
present  century.  In  late  years  they  have  undergone  a  con- 
spicuous decline  in  frequency.  The  last  extensive  epidemic 
of  yellow  fever  in  the  United  States  occurred  in  Louisiana, 
Mississippi,  and  Alabama  in  1878.  Severe  epidemics  occurred 
in  this  city  (Philadelphia)  in  1693,  1762,  1793,  and  1802.  In 
the  epidemic  of  1793,  the  most  serious  outbreak  of  the  dis- 
ease tliat  has  ever  occurred  in  a  city  of  the  Middle  States,  the 
mortality  for  the  four  months  of  its  continuance  was  about  10 
per  cent,  of  the  entire  population  of  the  cit}'. 

it  .should  Vje  considered  only  as  a  secondary  invader  in  yellow  fever.  We  find 
that  bacillus  X  (.Sternberg)  presents  marked  differences  from  the  foregoing 
microorganisms.  ..." 


YELLOIV  FEVER.  205 

Race  Susceptibility  and  Immunity. — Absolute  im- 
munity from  yellow  fever  is  not  possessed  by  any  peoples  as 
a  natural,  racial  characteristic. 

Relatively  speaking,  those  peoples,  be  they  Europeans, 
Africans,  or  Creoles,  who  are  permanent  residents  in  the 
endemic  zones  of  the  disease,  exhibit  less  susceptibility  than 
do  newly  arrived  strangers  from  the  colder,  more  northern  or 
southern  latitudes. 

According  to  Townsend  (quoted  from  Hirsch)  "  the  mor- 
tality of  vomito  ^  to  the  new-comer  from  the  cooler  latitudes 
may  be  said  to  be  in  an  exact  ratio  to  the  distance  from  the 
Equator  of  his  place  of  nativity  and  residence." 

Barton  presents  the  following  instructive  statistics  upon 
the  comparative  mortality  among  strangers  and  natives  in 
the  epidemic  at  New  Orleans  in  1853.  This  illustrates  very 
well  the  statement  made  by  Townsend. 

Of  each  1000  deaths  from  yellow  fever  that  occurred 
among  various   races  exposed  to  it,  there  were  of — 

Native  Creoles    ...  3-58 

Strangers  from  West  Indies,  Mexico,  and  South  America    .    .       6. 14 

"  "     Southern  United  States 13-22 

"  "     Spain  and  Italy 22.06 

"  "     Middle  United  States 30.69 

"  "     New  York  and  New  England 32-83 

"  "     Western  United  States 44-23 

"  "     France 48- 13 

"  "     British  America 50-24 

"  "     Great  Britain 52- 19 

"  "     Germany 132.01 

"  "     Scandinavia 163.26 

"  "     Austria  and  Switzerland 220.08 

"  "     The  Netherlands 328.94 

It  is  sometimes  said  that  the  Creole  and  the  African  are 
naturally  immune  from  yellow  fever.  This  is  not  true.  At 
birth  neither  of  these  peoples  is  insusceptible,  and  Guiteras 
states  that  "  the  foci  of  endemicity  of  yellow  fever  are  essen- 
tially maintained  by  the  Creole  infant  population." 

Since    a    single,   non-fatal    attack   of  yellow  fever   affords 

^  A  synonym  for  yellow  fever. 


206  JIYGIENE    OF   TRAXSMISSIBLE   DISEASES. 

more  or  less  complete  protection  from  subsequent  attacks, 
it  is  plain  that  by  prolonged  residence  in  the  zones  of  en- 
demicit}-  and  constant  exposure  to  infection  a  certain  propor- 
tion of  the  population,  including  all  races,  acquires  such 
resistance,  by  having  passed  safely  through  this  fever.  It 
is  interesting  to  note  that  the  so-called  "  acclimatization  "  to 
this  disease  that  many  natives  possess  is  more  or  less  com- 
pletely lost  after  removal  to  cooler  latitudes,  and  that  such 
indix'iduals  on  their  return  to  the  zone  of  endemic  yellow 
fever  often  exhibit  a  degree  of  susceptibility  equal  to  that  of 
total  strangers  to  the  district. 

Seasonal  and  Geographical  Influences. — Yellow 
fever  is  most  common  in  low  lands  along  the  coast,  and 
along  great  rivers  in  hot  climates.  It  rarely  or  never  occurs 
at  high  altitudes.  When  it  breaks  out  in  cities,  they  are  usu- 
ally low-lying,  badly-drained,  and  in  an  unsanitaiy  condition 
generally.  It  usually  appears  first  in  the  poor  and  over- 
crowded districts.  It  is  a  disease  of  summer,  though  it 
may  persist  for  a  time  after  the  advent  of  cool  weather. 
It  is  promptly  checked  by  frost,  though  this  does  not  per- 
manently eradicate  the  poison,  for  the  disease  may  reappear 
with  the  advent  of  warm  weather  again.  It  has  been  observed 
that  on  infected  ships  the  disease  will  sometimes  disappear  as 
they  sail  to  cooler,  northern  latitudes,  and  will  reappear  with 
return  to  the  warmer  climate. 

Dissemination. — The  tropical  districts  from  which  yellow 
fever  is  never  absent — i.  e.,  the  focal  zone — manifestly  offer 
certain  climatic  and  telluric  conditions  that  are  directly  favor- 
able to  the  development  and  perpetuation  of  the  yellow-fever 
virus.  Whether  this  virus  is  located  in  the  soil  or  in  the 
water  of  these  localities,  or  whether  it  is  disseminated  by 
the  water,  the  air,  or  by  insects,  it  is  impossible  to  say,  since 
nothing  vvliatever  is  known  as  to  its  nature  or  habitat. 

There  is  an  abundance  of  evidence  to  show  that  yellow 
fever  is  often  conveyed  from  place  to  place  along  lines  of 
traffic,  both  by  sea  and  land.  Ships  and  their  cargoes  are 
regarded  as  frequent  means  of  conveying  the  disea.se.  The 
poison  is  known  to  have  clung  persistently  to  the  hulls  of 


YELLOW  FEVER.  20/ 

particular  ships.  Old  wooden  ships  are  looked  upon  with 
much  greater  suspicion  than  are  the  more  modern  ones  built 
of  iron,  though  the  latter  are  by  no  means  proof  against  the 
invasion  of  the  poison.  From  time  to  time  an  outbreak  of 
the  disease  in  a  locality  is  coincident  with  the  arrival  and  un- 
loading of  a  ship  from  an  infected  port,  notwithstanding  the 
fact  that  she  may  have  had  no  cases  of  yellow  fever  among 
the  crew  or  passengers  during  the  voyage.  The  disease  is 
undoubtedly  conveyed  by  articles  of  merchandise,  mail  mat- 
ters, clothing,  and  other  objects  that  have  been  in  localities 
where  yellow  fever  is  epidemic.  Such  fomites  that  have  been 
in  the  immediate  vicinity  of  these  patients  are  considered 
especially  dangerous. 

Though  opinion  is  opposed  to  its  direct  transmission  from 
the  sick  to  the  well  (contagion),  still  there  are  good  grounds 
for  the  belief  that  patients  and  convalescents  have  been  the 
agencies  by  which  the  disease  has  been  carried  frOm  epidemic 
or  endemic  centers  into  other  localities  that  offered  conditions 
favorable  to  its  development.  It  appears  likely  that  the  mode 
of  dissemination  is  analogous  to  that  of  cholera  and  typhoid 
fever,  and  is  in  no  wise  similar  to  the  direct  transmission 
observed  in  small-pox,  measles,  and  other  highly  contagious 
maladies. 

Experience  has  shown  that  persons  in  attendance  on  the 
sick  are  not  especially  liable  to  contract  the  disease,  and 
yellow-fever  patients  have  often  been  brought  into  the  wards 
of  general  hospitals  among  susceptible  patients,  without  the 
disease  having  been  disseminated. 

Prophylaxis. — The  most  important  measure  against  the 
introduction  of  yellow  fever  into  a  locality  is  good  general 
sanitation,  including  clean  and  well-drained  streets,  proper 
disposal  of  garbage  and  excreta,  prevention  of  overcrowding, 
an  abundant  supply  of  pure  water  for  domestic  purposes, 
and  a  competent  system  of  quarantine. 

With  the  occurrence  of  the  disease  all  cases  should  be  iso- 
lated. Their  discharges,  including  those  from  the  bladder, 
bowels,  and  vomited  matters,  also  all  the  soiled  body-  and 
bed-clothing,  should  be  carefully  disinfected.    The  sick  cham- 


208  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

ber  should  be  clean  and  well  aired.  In  case  of  death  the 
body  should  be  wrapped  in  a  sheet  soaked  in  a  reliable  dis- 
infectant, placed  in  a  close  coffin,  and  buried  or  cremated  at 
once.  If  buried,  it  should  be  in  a  place  from  which  there 
would  be  no  danger  of  the  pollution  of  neighboring  water- 
supplies. 

Under  the  headings  "  Disinfection  of  Apartments "  and 
"  Disinfection  of  Ships  "  will  be  found  the  steps  necessary  to 
render  quarters  occupied  by  those  patients  free  from  danger. 


DENGUE, 


Definition. — A  specific,  epidemic,  febrile  disease  of  trop- 
ical and  subtropical  countries,  that  is  characterized  by  sud- 
denness of  onset,  severe  pains  in  the  muscles  and  articula- 
tions, the  appearance  of  an  initial  and  terminal  rash,  and  by  a 
tendency  to  terminate  favorably  in  from  three  to  four  days. 

It  is  also  variously  known  as  "  breakbone  fever,"  "  dandy 
fever,"  "three  days'  fever,"  etc.  It  is  certainly  infectious, 
though  no  micro-organism  has  as  yet  been  proved  to  stand 
in  causal  relation  to  it. 

Its  outbreak  is  favored  by  high  temperature  and  by  geo- 
graphical location  more  than  by  any  other  known  factors. 
It  is  most  apt  to  occur,  even  in  the  tropics,  during  the 
warmest  months.  In  higher  latitudes,  that  are  still  within  its 
epidemic  zone,  the  greatest  number  of  outbreaks  have  occur- 
red during  summer  and  early  autumn.  It  rarely  develops 
at  a  temperature  below  64°  F.  (Hirsch),  and  its  progress  is, 
as  a  rule,  suddenly  checked  by  the  onset  of  cold  weather  and 
the  occurrence  of  frost. 

It  is  a  disease  of  low-lying  localities  along  the  coast,  espe- 
cially of  overcrowded,  unsanitary  towns  and  cities.  It  rarely 
extends  into  the  country,  and  only  veiy  exceptionally  has  it 
been  observed  at  high  altitudes. 


DENGUE.  209 

Neither  physical  conditions  of  the  soil,  nor  such  meteor- 
ological influences  as  atmospheric  moisture,  rain,  and  wind, 
have  any  apparent  influence  upon  the  course  and  occurrence 
of  the  disease  so  long  as  the  temperature  remains  favorable. 

Neither  race,  age,  sex,  nor  social  condition  is  regarded  as 
a  conspicuous  factor  in  either  predisposing  to  or  protecting 
from  dengue. 

The  march  of  the  disease  through  a  community  is  often  so 
rapid  that  from  60  to  75  per  cent,  of  all  the  inhabitants  will 
be  affected  within  a  few  days  of  its  primary  appearance. 

By  certain  authors  dengue  is  said  to  simulate  yellow  fever 
in  some  respects.  By  others  it  is  regarded  as  predisposing 
to  subsequent  infection  by  yellow  fever,  cholera,  typhoid,  or 
malaria.  By  some  a  single  attack  is  thought  to  afford  pro- 
tection, by  others  this  is  denied. 

In  marked  contrast  to  the  severity  of  the  symptoms  of 
this  disease  stands  the  rarity  with  which  it  proves  fatal.  It 
is  apparently  dangerous  for  only  the  very  young  and  those 
of  the  aged  who  are  already  affected  with  grave  organic 
lesions.  Many  epidemics  pass  away  with  no  deaths  at  all, 
and  even  in  the  severest  the  number  of  deaths  has  "  not  yet 
reached  as  high  as  0.5  per  cent,  of  those  affected  "  (Scheube). 
It  is  said  to  occur  among  animals  (horses,  cows,  dogs,  and 
cats). 

Dengue  has  been  recognized  as  a  distinct  disease  since 
1824,  though  descriptions  of  an  identical  affection  occurring 
in  Egypt,  Spain,  Java,  and  India  v/ere  given  in  the  latter  part 
of  the  eighteenth  century.  During  the  present  century  it 
has  appeared  on  a  number  of  occasions  in  India,  Africa,  the 
West  Indies,  and  southern  United  States.  The  first  recog- 
nized epidemic  in  this  country  occurred  in  Savannah,  Ga.,  in 
the  fall  of  1826.  During  the  two  following  years  it  spread 
throughout  the  southern  States,  the  West  Indies,  and  the 
northern  coast  of  South  America.  Between  1848  and  1850 
and  in  1854,  widespread  epidemics  occurred  along  the  Mis- 
sissippi valley  and  in  the  southern  Atlantic  seaboard  States. 
The  last  epidemic  occurred  in  1873  in  Alabama,  Mississippi, 
and  Louisiana.     The  "  bilious  remitting  fever  "  described  by 

14 


2IO  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

Rush  in  1780,  as  occurring  in  Philadelphia,  is  regarded  by 
Hirsch  as  dengue  fever.  The  zone  of  epidemicity  of  this  dis- 
ease is  embraced  between  lat.  32°  47'  north  (Charleston, 
S.  C.)  and  23°  23'  south  (St.  Paulo,  Brazil)  (Hirsch). 

Dissemination. — It  is  questionable  if  dengue  is  con- 
tagious. At  first  sight,  its  rapid  spread  throughout  a  com- 
munity may  be  attributed  to  a  very  high  degree  of  con- 
tagiousness. On  further  inquiry,  however,  this  seems  to  be 
erroneous.  Like  influenza,  with  which  it  is  held  by  some  to 
be  closely  allied,  by  others  to  be  identical,  it  has  been 
observed  to  spring  up  suddenly  at  various  points  in  the  same 
locality  among  persons  who  have  had  no  communication 
with  one  another.  Its  rapid  spread  is  therefore  regarded  as 
due  more  to  the  simultaneous  infection  of  large  numbers  of 
individuals  from  a  common  focus  or  source,  rather  than  from 
the  transmission  of  the  morbific  material  from  person  to  per- 
son. Again  like  influenza,  it  is  believed  to  be  carried  from 
place  to  place  along  lines  of  travel  by  land  and  sea.  After 
the  subsidence  of  an  epidemic  it  occasionally  happens  that, 
in  places  of  suitable  temperature,  dengue  remains  endemic 
for  a  time. 

Prophylaxis. — As  a  rule,  special  preventive  measures 
against  dengue  have  not  been  practised,  probably  because 
of  the  comparative  rarity  with  which  the  disease  proves  fatal ; 
and  indeed,  until  we  possess  some  knowledge  of  its  exciting 
cause  and  of  its  mode  of  dissemination,  it  will  be  difficult  to 
institute  a  rational  system  of  prophylaxis.  The  fact  of  its 
sudden  and  simultaneous  occurrence  among  groups  of  indi- 
viduals in  the  same  locality,  who  have  in  no  known  way 
been  exposed  to  contagion,  and  of  the  coincidence  of  epi- 
demics in  different  places,  illustrates  the  insidious  nature  of 
its  dissemination  and  the,  for  the  time  being,  ubiquity  of  the 
poison.  Isolation  of  the  sick,  with  disinfection  of  excreta, 
clothing,  and  apartments,  might  be  practised,  but  it  is  doubt- 
ful if  this  would  prove  of  any  marked  influence  in  checking 
the  march  of  the  epidemic. 


TYPHUS  FEVER.  211 


TYPHUS  FEVER. 


Definition. — A  specific,  contagious  fever  characterized  by 
a  maculated  rash,  extreme  depression  of  the  vital  powers, 
nervous  derangements,  and  a  tendency  for  non-fatal  cases  to 
terminate  by  crisis  in  about  two  weeks. 

It  is  also  variously  known  as  "  spotted  fever,"  "  jail  fever," 
"  camp  fever,"  "  ship  fever,"  and  "  hospital  fever."  Its  spe- 
cific exciting  cause  is  not  known,  though  doubtless  such  a 
factor  exists.  It  is  universally  admitted  that  the  most  impor- 
tant influences  that  predispose  to  its  epidemic  occurrence  are 
widespread  destitution  and  misery,  with  their  usual  concom- 
itants— viz.,  overcrowding,  filth,  poor  and  insufficient  food, 
intemperance,  and  inadequate  clothing  and  shelter. 

In  former  years  epidemics  of  typhus  fever  occurred  with 
comparative  frequency,  both  in  Europe  and  in  this  country ; 
but  latterly — /.  c,  during  the  past  twenty-five  years — by 
reason  of  the  sanitary  improvement  that  conditions  of  life 
have  everywhere  undergone,  its  visitations  have  become  fewer 
until  it  has  practically  disappeared,  as  a  dreaded  pest,  from 
among  civilized  peoples. 

Distribution. — The  occurrence  of  typhus  fever  is  not 
markedly  influenced  by  geographical  location,  though  it  is 
usually  regarded  as  more  likely  to  occur  in  temperate  and 
cold  than  in  the  warmer  climates,  possibly  because  of  the  con- 
ditions favorable  to  open-air  life  that  the  latter  afford. 

Its  epidemic  outbreak  is,  as  a  rule,  referable  to  the  pre- 
disposing influence  of  the  social  condition  of  the  people 
among  whom  it  occurs.  The  history  of  the  disease,  during 
the  time  when  it  was  more  frequent  than  it  is  to-day,  points 
directly,  as  stated  above,  to  widespread  destitution  and  mis- 
ery, with  all  that  they  entail,  as  the  important  factors  in  de- 
termining the  development  of  an  epidemic.  Up  to  about  the 
middle  of  the  present  century  it  had  occurred  epidemically  in 
many  parts  of  both  the  eastern  and  western  hemispheres. 

Australia,  New  Zealand,  Japan,  a  large  part  of  Africa,  and 
parts  of  southern  Europe  have  been  comparatively  free  from 
the  disease.     According  to  Hirsch,  endemic  centers  have  be- 


212  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

come  established  in  only  a  few  countries,  notably  in  Ireland, 
Russia,  and  Italy,  and  even  here  they  are  of  but  limited  ex- 
tent. Telluric  and  seasonal  influences  do  not  appear  to  be 
of  much,  if  any,  importance  in  deciding  an  epidemic  out- 
break. 

In  1883  a  small  epidemic  of  typhus  fever  occurred  in  the 
Philadelphia  Hospital,  and  in  1881  to  1882  over  700  cases 
were  admitted  to  the  Riverside  Hospital  in  New  York. 
Other  than  these,  there  have  been  no  outbreaks  of  any 
moment  in  this  country  since  those  that  occurred  between 
1867  and  1870. 

Dissemination. — Typhus  fever  is  highly  contagious,  in 
the  strict  sense  of  the  word,  and  there  is  probably  no  disease 
that  has  been  more  frequently  contracted  from  patients  by 
physicians  and  nurses.  The  specific  virus,  of  whatever  nature 
it  may  be,  appears  to  be  distinctly  transmissible  from  the  sick 
to  the  well  through  the  surrounding  air.  Whether  it  is  usually 
received  by  way  of  the  air-passages,  or  through  the  alimen- 
tary tract,  or  whether  infection  may  occur  through  wounds, 
cannot  be  stated,  as  nothing  is  known  of  the  causative  agent. 

The  poison  may  be  harbored  by  and  carried  from  place  to 
place  in  fomites.  As  stated,  the  activities  of  the  specific 
virus  are  favored  by  unsanitary  conditions,  and  if  cases  of  the 
disease  be  introduced  into  overcrowded,  filthy,  and  generally 
unhygienic  localities,  there  is  every  likelihood  of  an  epidemic 
outbreak  of  the  fever.  By  some  writers  it  is  believed  to  be 
carried  from  the  sick  to  the  well  by  insects. 

The  disease  is  less  common  among  the  very  young  and 
the  aged  than  during  the  periods  of  youth  and  early  maturity. 
Its  occurrence  is  not  influenced  by  sex. 

Prophylaxis. — It  is  manifest  that  the  most  important 
prophylactic  measures  against  this  fever  are  those  that  aim  to 
prevent  its  introduction  from  without,  and  those  that  are  de- 
signed to  eliminate  ail  local  conditions  favorable  to  its  devel- 
opment. 

The  former  comprise  the  functions  of  such  properly  con- 
stituted .sy.stems  of  quarantine  as  should  exi.st  at  all  populous 
.seaports  ;  the  latter  represent  the  duties  of  legally  author- 


TYPHUS  FEVER. 


213 


ized  boards  of  health.  The  scope  of  the  work  should  em- 
brace the  strict  sanitary  supervision  of  overcrowded  localities, 
such  as  exist  in  all  the  poorer  districts  of  great  centers  of 
population,  and  should  be  especially  directed  to  the  general 
hygiene  of  places  designed  for  both  permanent  and  tempor- 
ary residence  by  people  of  such  localities — as,  for  instance, 
tenement-houses,  work-shops  and  work-houses,  jails,  reform- 
atories, almshouses,  and  hospitals.  Especial  attention  should 
be  given  to  the  cleanliness,  the  ventilation,  the  condition  of 
crowding,  the  water-supply,  and  the  sewage  of  these  places. 
Careful  watch  should  be  kept  for  the  occurrence  of  suspicious 
cases,  and  these  should  be  isolated  in  properly  equipped  hos- 
pitals as  soon  as  detected. 

The  influence  of  fresh  air  upon  the  virulence  and  vitality 
of  the  virus  of  this  disease  is  apparently  of  very  great  im- 
portance, and  many  of  those  who  have  observed  the  epidemic 
outbreak  of  typhus  fever  in  hospitals  have  been  struck  by  the 
rapidity  of  its  disappearance  when  the  patients  were  removed 
from  the  wards  and  placed  in  tents  in  the  open.  Isolation  in 
freely  ventilated  apartments,  and  careful  disinfection  of  bed- 
and  body-clothing  and  excreta  are  always  called  for.  Isola- 
tion should  be  rigidly  enforced,  because  of  the  highly  con- 
tagious nature  of  the  disease ;  and  for  the  same  reason  the 
physician  and  attendants  should  spend  no  more  time  than  is 
necessaiy  in  the  immediate  proximity  of  the  patient. 

The  sick  chamber,  as  well  as  all  furniture  and  other  arti- 
cles contained  in  it,  should  be  disinfected  and  thoroughly 
aired  after  the  removal  of  the  patient. 


214  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

RELAPSING  FEVER. 

Definition. — "  Relapsing,"  "  Famine,"  or  "  Seven  Days' 
Fever,"  is  an  infectious  disease  that  results  from  the  presence 
in  the  blood  of  a  specific  micro-organism  discovered  by  Ober- 
meier  and  now  generally  known  as  spiroclueta  Obcnncin. 

The  disease  is  characterized  by  acute  febrile  paroxysms 
that  last  from  six  to  seven  days.  These  are  followed  by  an 
intermission  of  the  same  length  of  time,  when  the  acute 
symptoms  reappear.  It  is  from  the  occurrence  of  these  re- 
lapses that  the  fever  takes  its  name. 

The  organism  causing  the  disease  is  a  spiral-shaped  thread 
that  may  be  seen  moving  about  among  the  corpuscles  in 
blood  drawn  during  the  paroxysms  (Fig.  25).     They  disap- 


FlG.  25. — Showing  spirochseta  of  Obermeier  in  blood  of  relapsing  fever  patient. 

pear  from  the  blood  until  the  crisis  of  the  fever,  and  are  but 
very  rarely  to  be  detected  during  the  period  of  intermission. 
In  dried  blood  preparations  the  spirochaeta  may  be  stained 
by  the  usual  methods.  It  is  decolorized  by  Gram's  method. 
It  varies  in  length,  being  sometimes  hardly  longer  than  the 
diameter  of  a  red  corpuscle,  while  at  other  times  it  is  many 
times  this  length.  Nothing  is  known  of  its  life  hi.story.  It 
has  never  been  reared  artificially. 

By  inoculation  with  blood  from  these  patients  the  disease 


RELAPSING  FEVER.  21$ 

has  been  induced  in  men  and  in  monkeys,  though  in  the  lat- 
ter only  the  primary  acute  fever  occurs  and  there  is  no  ten- 
dency to  recur.  The  organism  has  been  kept  alive  outside 
the  human  body  for  about  a  week,  by  keeping  on  ice  leeches 
that  have  been  allowed  to  fill  themselves  with  blood  from 
these  patients. 

The  conditions  that  favor  the  development  of  typhus  fever 
— viz.,  squalor,  filth,  destitution,  etc. — likewise  favor  the  de- 
velopment of  relapsing  fever,  and  the  two  diseases  have  been 
observed  together  in  the  same  locality. 

Distribution. — Quoting  Hirsch,  the  first  trustworthy 
account  that  we  have  of  this  disease  on  European  soil  is 
given  by  Rutty  in  1 770  in  his  chronological  history  of  the 
prevailing  diseases  of  Dublin.  In  this  publication  he  directs 
attention  to  an  epidemic  of  this  fever  that  occurred  in  Dub- 
lin in  1739.  The  fever  has  been  more  prevalent  in  Ireland, 
Scotland,  Russia,  parts  of  Germany,  northern  Africa,  and 
India  than  elsewhere.  It  had  not  appeared  in  Australia  up 
to  1875.  It  was  first  observed  in  this  country,  in  Philadel- 
phia, in  1844.  It  has  not  appeared  in  the  United  States  in 
epidemic  form  since  1869,  when  it  prevailed  extensively  in 
New  York  and  Philadelphia. 

It  is  not  apparently  influenced  by  age,  sex,  season,  or  tel- 
luric conditions,  though  it  is  said  to  have  occurred  more  fre- 
quently in  the  temperate  and    cold  than  in  warm  climates. 

Dissemination. — It  is  said  to  be  contagious,  though  less 
so  than  is  typhus  fever.  Latterly,  attention  has  been  directed 
to  the  possibility  of  its  being  spread  from  the  sick  to  the  well 
by  the  bites  of  insects — a  reasonable  opinion  in  view  of  the 
fact  that  the  disease  may  be  induced  through  the  inoculation 
of  healthy  persons  with  blood  from  those  suffering  from  the 
fever. 

The  causative  agent  is  said  to  be  transmissible  by  fomites. 

Prophylaxis. — Since  the  social  conditions  that  favor  the 
development  of  typhus  likewise  favor  the  development  of 
relapsing  fever,  the  prophylactic  measures  recommended  for 
the  former  serve  equally  well  for  the  latter  disease. 


2l6  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

RABIES. 

( Lyssa  ;  Hydrophobia.  ) 

Definition,  Cause,  etc. — A  specific  infectious  disease 
communicable  from  animals  to  animals  and  to  man,  com- 
monly by  a  bite. 

When  occurring  in  animals  it  is  known  as  rabies  or  lyssa ; 
when  in  man,  as  hydrophobia,  not  because  of  the  actual  fear 
of  water,  as  the  name  signifies,  but  rather  because  of  the 
dread  felt  by  the  patient  of  the  severe  spasm  of  the  muscles 
of  deglutition  that  is  experienced  in  efforts  to  swallow  water. 

In  the  rabid  animal  the  virus  of  the  disease  is  contained  in 
the  saliva,  and  it  is  through  wounds  made  with  the  teeth,  or 
wounds  to  which  saliva  from  such  animals  gains  access,  that 
rabies  is  transmitted. 

Numerous  efforts  have  been  made  to  detect  the  etiological 
factor  of  rabies,  but  as  yet  no  trustworthy  results  have  been 
reached.  Nevertheless,  it  has  been  demonstrated  that  a 
poison  is  present  in  the  tissues  of  animals  suffering  from  or 
dead  of  the  disease — especially  in  the  tissues  of  the  central 
nervous  system — that  is  capable  of  setting  up  the  disease  in 
other  animals  into  which  may  be  inoculated.  Though  the 
actual  cause  of  rabies  has  not  been  detected,  still,  the  behavior 
of  the  tissues  that  are  particularly  rich  in  the  poison  corre- 
sponds in  so  many  ways  with  that  of  tissues  containing  a 
living  virus  as  to  leave  little  doubt  that  the  disease  originates 
with  the  invasion  of  a  specific  micro-organism,  or  the  intro- 
duction of  a  poison  resulting  from  the  development  of  such 
an  organism.  Thus,  for  instance,  the  poisonous  properties 
of  the  medulla  are  destroyed  in  a  few  minutes  by  exposure  to 
50°  C,  by  subjection  to  various  disinfectants,  by  prolonged 
action  of  sunlight,  and  by  drying,  all  of  which  reactions,  as 
we  know,  are  common  to  tissues  containing  living  micro- 
organisms. 

The  animals  most  frequent!}'  affected  are  dogs,  wolves, 
cats,  jackals,  and  skunks,  though  the  di.sease  is  transmissible 
to  horses,  bovines,  swine,  sheep,  deer,  etc.  When  once  well 
established,  the  di.sease  is  almost  invariably  fatal.     The  dog 


RABIES. 


217 


is  the  chief  sufferer  from  rabies,  and  is  the  principal,  if  not  the 
sole,  means  of  its  propagation  (see  Table  XI.). 

Table  XI. —  Compiled  by  Fleining,  giving  the  number  of  cases  of 
rabies,  and  the  species  of  animal  in  wliicli  they  occurred,  in 
England  during  the  four  years  ending  with  i8go  .•' 


Kind  of  Animal. 


Dogs   .  .  . 

Cattle  .  . 

Sheep  .  . 

Swine  ,  , 

Horses  .  . 

Deer    .  .  . 
Total 


IS37. 

1888. 

1S89. 

1890. 

129 

217 

160 

312 

II 

2 

9 

2 

5 

7 

II 

3 

4 

I 

4 

5 

4 

2 

257 

2 

497 

176 

340 

134 

Rabies  is  communicable  to  man,  as  stated,  by  the  bite  of  a 
rabid  animal.  Bites  received  upon  exposed  surfaces,  as  upon 
the  head,  face,  and  hands,  are  usually  more  serious  and  more 
<:ertain  to  be  followed  by  hydrophobia  than  are  those  upon 
the  clothed  portions  of  the  body,  owing,  doubtless,  in  the 
latter  case,  to  the  virus  being  wiped  from  the  teeth  in  their 
passage  through  the  clothing. 

The  period  of  incubation  of  hydrophobia  ordinarily  varies 
from  about  six  weeks  to  two  months,  according  to  circum- 
stances. In  some  cases  it  is  shorter — as  short  as  two  weeks ; 
in  others  it  may  be  delayed  for  a  year  or  more  after  the 
reception  of  the  bite.  The  bite  of  the  rabid  wolf  and  cat  is 
more  certain  to  be  followed  by  hydrophobia  than  is  that  of 
the  dog. 

The  fatality  among  individuals  bitten  by  dogs  proven  to 
Jiave  rabies  is  in  general  15  per  cent.,  while  for  those  cases  in 
which  the  bites  were  received  upon  exposed  surfaces  the 
figure  rises  to  from  60  to  80  per  cent.  No  country  is  exempt 
from  rabies  except,  perhaps,  Australia  and  New  Zealand 
(Fleming),  and  it  is  excluded  from  those  places  only  through 
a  careful  quarantine  of  all  dogs  coming  into  the  country. 

It  is   more   prevalent   in   some   countries   than   in   others, 

^  See  Fleming:  "The  Propagation  and  Prevention  of  Rabies,"  Trans. 
.Seventh  Internat.  Cong.  Hygiene  and  Demography,  1891,  vol.  iii.,  p.  16. 


2l8  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

owing  in  part  to  the  stringency  of  dog  laws  in  localities 
where  it  is  rare,  and  the  laxity  or  absence  of  such  laws  from 
those  places  in  which  it  is  more  common. 

Rabies  is  especially  prevalent  in  Russia,  Belgium,  Austria^ 
France,  and  England.  It  is  rare  in  Germany  and  Switzer- 
land, because  of  the  regulations  governing  dogs,  and  for 
some  reason  or  another  it  is  not  very  common  in  this  coun- 
try. The  cases  seen  in  Germany  have,  in  the  majority  of 
instances,  been  in  the  provinces  along  the  Russian  border. 

Since  the  dog  is  the  most  frequent  sufferer  from  this  dis- 
ease, and  the  commonest  source  from  which  hydrophobia  is 
contracted  by  human  beings,  it  is  manifestly  important  that 
it  should  be  recognized  in  its  earliest  stages. 

Symptoms. — A  dog  bitten  by  another  that  is  mad  may 
show  signs  of  rabies  within  a  few  days — ten  to  fifteen — or,  as 
in  latent  rabies,  evidence  of  the  disease  may  not  appear  for 
months.  The  symptoms  of  rabies  in  the  dog  warrant  the 
division  into  "  furious  "  or  "  excitable,"  and  "  paralytic  "  or 
"  dumb "  rabies,  though  sharp  lines  of  distinction  cannot 
always  be  drawn.  After  the  earliest  signs  of  madness,  that 
usually  manifest  themselves  by  quietness,  sullenness,  dis- 
inclination for  company,  alterations  in  the  general  psychical 
nature,  perverted  appetite,  and  conspicuous  alteration  in 
voice,  the  animal  may  become  markedly  excited  or  furious^ 
or  paralysis  may  set  in.  If  the  former,  he  will  often  trot 
about  over  large  tracts  of  country,  with  head  and  tail  de- 
pressed, tongue  hanging  from  the  jaws,  and  snapping  ^  at  all 
objects  that  come  in  his  way.  It  is  in  this  stage  that  the  dog 
is  most  dangerous  to  other  animals. 

From  loss  of  food  and  sleep  and  excessive  nervous  excite- 
ment the  animal  rapidly  becomes  emaciated  and  haggard. 
Death  usually  results  in  a  convulsion,  of  which  the  dog  may 
have  many  toward  the  later  stages  of  the  disease. 

If  the  disease  assumes  the  paralytic  form,  there  is  usually 
no  period  of  excitement ;  but  after  the  preliminary  symptoms 
evidences  of  paralysis,  beginning  with  the  muscles  about  the 

'Responsible  authors  do  not  regard  the  "snapping"  as  deliberate,  but 
rather  as  reflex. 


RABIES.  219 

face  and  jaws — especially  of  the  lower  jaw — are  observed. 
Paralysis  is  progressive  until  the  death  of  the  animal. 

While  the  clinical  aspects  of  these  manifestations  of  rabies 
are  totally  dissimilar,  they  are  still  regarded  as  etiologically 
identical,  and  do  not  therefore  constitute  distinct  diseases. 

The  mode  of  diagnosing  rabies  that  is  now  regarded  as  the 
most  trustworthy  is  only  possible  after  the  death  of  the  ani- 
mal, but  even  then  it  is  manifestly  often  of  the  utmost  impor- 
tance to  know  definitely  the  nature  of  the  malady,  in  the 
event  of  the  dog's  having  bitten  persons  or  other  animals. 

This  method  of  diagnosis  consists  in  the  introduction  of  a 
small  portion  of  the  medulla  from  the  mad  dog  beneath  the 
dura  mater  of  a  rabbit.  After  a  period  of  incubation  of  from 
twelve  to  eighteen  days,  the  rabbit  evinces  beginning  paraU 
ysis ;  this  is  progressive  until  death.  The  form  of  rabies 
thus  transmitted  to  the  rabbit  is  always  paralytic,  though 
the  same  material  may  be  capable  of  inducing  either  the 
furious  or  the  paralytic -A^ariety  in  dogs  inoculated  in  a  simi- 
lar manner.  By  the  repeated  transference  of  bits  of  medulla 
from  one  rabbit  to  another,  by  this  mode  of  inoculation,  the 
disease  may  be  propagated  at  will. 

Prophylaxis. — The  statistics  on  this  disease  from  differ- 
ent countries,  without  exception,  demonstrate  that  adequate 
laws  concerning  the  keeping  of  dogs,  when  properly  enforced, 
constitute  the  most  potent  factor  for  its  suppression.  Such 
regulations  should  provide  for  : 

The  immediate  destruction  of  all  dogs  known  or  believed 
to  be  suffering  from  rabies,  and  the  secure  isolation  and  care- 
ful observation  of  all  animals  that  may  have  been  bitten  by 
such  dogs. 

The  seizure  and  destruction  of  all  vagrant  dogs. 

The  imposition  of  a  tax  upon  the  owners  of  dogs,  and 
the  punishment  by  fine  of  all  persons  detected  in  evading 
this  tax. 

During  the  prevalence  of  rabies,  and  for  a  time  afterward 
equivalent  to  the  longest  period  of  latency,  all  dogs  should  be 
muzzled.  The  non-observance  of  this  provision  on  the  part 
of  the  owners  to  be  punishable  with  fine. 


220  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

There  are  numerous  instances  in  which  the  adoption  of 
such  regulations  has  caused,  within  a  short  time,  the  almost 
total  disappearance  of  rabies  from  neighborhoods  in  which  it 
prevailed.  Thus,  for  instance,  there  were  107  mad  dogs 
killed  in  Berlin  during  an  outbreak  of  the  disease  in  1852; 
on  July  2,  1853,  a  decree  was  issued  to  the  effect  that  all 
dogs  should  be  muzzled,  and  all  not  so  secured  should  be 
killed ;  in  the  year  following  this  decree  there  was  only  one 
dog  destroyed  as  rabid.  It  was  subsequently  found  necessary 
to  extend  this  decree  to  the  whole  of  Prussia,  as  the  muzzling 
and  destruction  of  dogs  in  Berlin  alone  were  not  sufficient  to 
eradicate  the  disease  totally. 

Within  eighteen  months  after  the  adoption  of  the  muzzling 
law  in  Vienna  rabies  was  totally  suppressed.  In  the  Grand 
Duchy  of  Baden  the  numbers  of  cases  of  rabies  that  occurred 
annually,  from  1871  to  1875  inclusive,  were  18,  37,  50,  and 
43.  In  1876  the  muzzle  was  applied,  with  the  following 
results  :  in  1876  there  were  28  cases ;  in  1877,  3  ;  in  1878,  4; 
in  1879,  2;  in  1880,  2;  in  1881,  2;  in  1882,  3;  in  1883,  2; 
in  1884,  2. 

In  Prussia  preventive  measures  have  reduced  the  deaths 
from  hydrophobia  in  human  beings  from  a  yearly  average  of 
166  cases  for  the-  ten  years  ending  with  1879,  to  a  yearly 
average  of  4.5  cases  for  the  decade  ending  with   1886. 

The  foregoing  statistics,  taken  from  Fleming's  paper,  re- 
ferred to  above,  while  representing  only  a  portion  of  the 
material  presented  by  him  in  support  of  his  argument  for 
the  suppression  of  rabies,  are  still  sufficient  for  our  purpose 
to  demonstrate  what  may  be  accomplished  by  intelligent  and 
conscientious  attention  to  this  important  subject. 

Preventive  Inoculation. — The  principles  involved  in 
the  practice  of  preventive  inoculations  against  rabies  and 
hydrophobia  are  essentially  those  on  which  all  other  modes 
of  preventive  inoculation  are  based ;  that  is  to  say,  they  con- 
template the  establishment  in  the  animal  under  treatment  of 
a  tolerance  to  the  virus  of  the  particular  disease  from  which 
it  is  being  protected.  Tliis  is  usually  accomplished  by  the 
repeated  inoculation  of  doses  of  the  virus  that  are  so  small, 


RABIES.  221 

or  of  virus  so  attenuated  in  potency,  as  not  to  imperil  the  life 
of  the  animal,  beginning  usually  with  very  minute  doses  and 
gradually  increasing  them  until  the  animal  can  finally  with- 
stand, without  injury,  what  would  otherwise  be  a  fatal  dose 
of  the  fully  virulent  virus.  When  this  point  is  reached,  the 
animal  is  protected.  In  the  majority  of  instances  the  protec- 
tion thus  afforded  is  believed  to  be  due  to  specific  systemic 
reactions,  following  upon  each  injection,  by  which  the  tissues 
acquire  a  tolerance  to  the  poisonous  properties  of  the  mate- 
rials used.  In  this  particular  instance,  as  indeed  in  all 
others,  the  essential  starting-point  is  a  virus  of  fixed  and 
known  toxicity. 

The  virus  obtained  from  the  medulla  of  a  dog  dead  from 
the  ordinary  rabies  of  the  street  ("  rage  des  rues "),  when 
inoculated  into  a  rabbit,  has  a  period  of  incubation  of  from 
fifteen  to  twenty  days,  rarely  or  never  less  than  eleven  days. 
By  passing  such  virus  from  rabbit  to  rabbit  through  a  long 
series,  the  incubation  period  becomes  gradually  shortened 
until  it  finally  reaches  a  fixed  point  of  from  six  to  seven  days 
("  virus  fixe ").  As  a  rule,  this  is  the  strongest  and  most 
stable  virus  that  can  be  obtained. 

If  the  medulla  from  a  rabbit  that  has  died  after  inoculation 
with  this  fixed  virus  be  preserved  in  a  dry  atmosphere,  its 
toxicity  gradually  becomes  lessened  as  the  drying  proceeds, 
and  totally  disappears  in  about  two  weeks  if  the  drying  has 
been  at  a  temperature  of  from  23°  to  25°  C.  With  the  me- 
dulla so  treated  the  period  of  incubation,  as  determined  by 
the  inoculation  of  rabbits,  becomes  longer  as  the  virus  be- 
comes attenuated  in  the  degree  of  its  potency.  In  Pasteur's 
protective  inoculation,  the  treatment  is  begun  with  the  subcu- 
taneous injection  of  emulsions  of  spinal  cords  or  medullae 
that  have  been  thus  dried  until  almost  robbed  of  their  toxic 
properties  ;  this  is  followed  by  similar  injections  of  emulsions 
from  more  and  more  toxic  tissues,  until  finally  the  animal  is 
prepared  for  an  injection  with  the  strongest — i.  e.,  "  fixed 
virus  ; "  when  this  stage  is  reached,  protection  is  assumed  to 
be  completed. 

For  the  successful  employment  of  this  method  it  is  essen- 


222  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

tial  that  it  be  begun  at  the  earliest  possible  moment  after  the 
reception  of  the  virus — i.  c,  after  the  bite  of  the  rabid  ani- 
mal. The  greater  the  delay  the  less  likely  is  the  treatment  to 
be  effectual. 

The  influence  of  this  mode  of  treatment  upon  the  mortal- 
ity from  hydrophobia  among  human  beings  bitten  by  rabid 
animals  is  so  striking  as  to  efface  all  question  as  to  its  efficacy. 
As  stated  above,  a  fair  average  mortality  for  all  cases  of  bites 
from  mad  animals  is  1 5  per  cent.,  while  the  mortality  among 
those  bitten  upon  the  head,  face,  neck,  and  hands,  ranges 
from  60  to  80  per  cent.  The  following  table,  compiled  by 
Pottevin,  illustrates  the  striking  reductions  in  these  death- 
rates  that  have  been  accomplished  through  this  mode  of  treat- 
ment in  the  Institute  Pasteur  at  Paris. 

Table  showing  the  results  of  the  Pasteiirian  preventive  inoculation 
against  hydrophobia  in  human  beings,  for  the  twelve  year's 
endi?ig  with  iSgj  :^ 

Years.  Persons  treated.  Deaths.  Mortality 

(per  cent.). 

1886 2671  25  0.94 

1887 1770  14  0.79 

1888 1622  9  0.55 

1889 1830  7  0.38 

1890 1540  5  0.32 

1891 1559  4  025 

1892 1790  4  0.22 

1893 1648  6  0.36 

1894 1387  7  0.50 

1895 1520  5  0.33 

1896 1308  4  0.30 

1897 1521  6  0.39 

'See  Les  Vaccinations  Antirabiqiics  a  f Inslitiit  Pasteur  en  iSgj,  par 
Henri  PcHtevin  ;  Amtales  de  I' Institut  Pasteur,  1898,  tome  xii.,  p.  301. 


DISEASES  DUE    TO  ANIMAL   PARASITES.  223 

DISEASES  DUE  TO  HIGHLY-DEVELOPED  ANIMAL 
PARASITES. 

It  is  manifestly  inadvisable  to  attempt  in  a  book  of  this 
character  the  detailed  treatment  of  so  large  a  subject.  The 
following  must,  therefore,  be  regarded  as  a  mere  sketch  of 
the  more  frequent  and  important  conditions  observed  in  man 
as  a  result  of  the  invasion  of  the  body  by  the  commoner  ani- 
mal parasites. 

As  has  been  already  intimated  in  the  first  section,  the  dis- 
turbance of  physiological  function  and  the  morbid  conditions 
that  arise  from  the  presence  of  entozoa  in  the  body  are  in  the 
main  due  to  their  character,  mode  of  development,  their  local 
irritation,  to  the  demands  that  they  make  upon  the  blood  and 
tissues  for  nutrition,  and  to  their  obstructive  action  when  lo- 
cated in  important  viscera  and  organs  of  special  sense.  With 
the  exception  of  the  blood-sucking  ankylostonia  dtiodenale, 
those  that  occupy  the  alimentary  tract  cause  only  disturbances 
of  the  digestive  processes  and  reflex  nervous  phenomena,  and 
are  not  accompanied  by  definite  or  serious  structural  lesions. 
Those  located  within  the  tissues  cause  irritation  which  may 
in  time  be  followed  by  more  or  less  of  inflammatory  reaction. 
Certain  of  these,  by  developing  to  an  unusual  size  (echino- 
coccus  cyst),  may  seriously  obstruct  the  functional  activity  of 
the  organ  in  which  they  are  located ;  while  those  occupying 
a  position  in  such  important  vital  parts  as  the  central  nervous 
system,  the  organs  of  special  sense,  and  the  circulatory  ap- 
paratus, may  result  in  the  gravest  disturbances,  and  even  in 
death. 

Diseases  of  this  class,  and  especially  those  in  which  the 
parasite  resides  within  the  alimentary  tract  or  internal  viscera, 
are  most  frequently  contracted  through  the  swallowing  of 
either  the  mature  parasite  or  its  eggs,  or  its  larval  forms. 

As  a  rule,  the  commonest  worms  of  man  enter  the  body  as 
larvae  with  the  flesh  of  animals  in  which  the  first  stages  of 
development  of  the  worm  have  taken  place ;  or  in  some  in- 
stances they  may  be  derived  directly  from  domestic  animals 
whose  flesh  is  not  used  as  food,  but  with  which  the  individual 


224  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

may  have  been  in  intimate  association  ;  or  in  other  cases  they 
may  be  traced  to  the  eggs  of  parasitic  worms  that  are  con- 
tained in  polluted  drinking  water. 

The  Nematoda. — These  worms  are  so  called  because 
of  their  filiform  or  thread-like  shape.  The  commonest  spe- 
cies are  : 

Ascaris  Lumbricoides  {Round  WoriJi). — It  is  in  general 
similar  in  appearance  to  the  ordinary  earth-worm.  The  fe- 
males measure  about  30  cm.  (12  inches),  and  the  males  about 
1 5  cm.  (6  inches)  in  length.  It  locates  in  the  small  intestine 
of  man,  and,  as  development  proceeds,  a  large  number  of 
eggs  are  passed.  The  eggs  are  brownish  in  color,  as  seen  in 
the  stools,  and  are  of  a  barrel  shape.  The  eggs  are  carried 
by  water,  and  it  is  through  the  drinking  of  water  polluted  with 
them  that  the  individual  often  becomes  infected.  The  worm 
is  also  seen  in  swine,  and  for  this  reason  water  polluted  with 
hog  excrement  should  be  viewed  with  suspicion. 

Oxyuris  Vermicularis  {Thread  Worni). — This  worm  in- 
vades the  cecum  and  upper  colon.  The  female,  which  is 
about  12  mm.  in  length,  deposits  eggs  in  very  large  numbers. 
Within  these  eggs  spermatozoa-like  embryos  may  often  be 
detected.  When  swallowed,  the  envelope  of  the  embryo  is 
digested  by  the  gastric  juice  and  the  larvae  liberated.  They 
pass  through  the  early  developmental  stage  in  the  upper  in- 
testine and  reach  maturity  in  from  twenty -five  to  thirty  days. 
Raw  vegetables  or  insufficiently  cooked  vegetables  are  said 
to  be  the  most  frequent  source  of  infection.  The  larvae  are 
destroyed  by  long  immersion  in  water. 

Trichocephalus  dispar  {ivliip-zuonri)  is  the  commonest 
intestinal  parasite  of  man  in  tropical  latitudes.  It  retains  its 
vitality  in  water  and  in  moist  soil.  The  embryos  in  the  Qgg 
are  very  tenacious  of  life.  When  the  o.^^  is  swallowed,  the 
larva  is  liberated  in  the  alimentary  canal,  attaches  itself  to 
the  wall  of  the  intestine  by  its  lash-like  extremity,  and  pro- 
ceeds to  develop  slowly,  reaching  maturity  after  about  ten  or 
twelve  months. 

Ankylostoma  duodenale  is  a  minute  worm,  which  by  its 
presence  in  the   upper  portion  of  the  small  intestine  causes 


DISEASES  DUE    TO   ANIMAL    PARASITES.  22$ 

the  disease  called  ankylostomiasis,  or  Egyptian  chlorosis^ 
The  parasite  becomes  attached,  often  in  enormous  numbers, 
to  the  villi  of  the  duodenal  mucous  membrane.  Through 
the  continuous  draught  that  it  makes  upon  the  circulating 
blood  there  results  the  condition  of  anemia  by  which  the  dis- 
ease is  characterized  clinically,  and  from  which  it  takes  its 
popular  name.  The  parasite  is  apparently  widely  distributed, 
as  the  disease  has  been  observed  in  Egypt,  India,  Italy, 
Africa,  Peru,  and  Australia.  An  analogous  disease,  known 
as  "  miners'  cachexia,"  "  miners'  chlorosis,"  "  tunnel  disease," 
has  been  observed  among  Italian  workmen  in  the  St.  Goth- 
ard  tunnel.  It  has  also  been  known  among  Italian  brick- 
makers  and  in  those  who  have  worked  upon  the  irrigation 
fields.  The  disease  is  said  to  have  been  known  for  some 
years  among  the  coal  miners  of  Belgium  and  the  brick- 
makers  of  Cologne  as  "  brick-makers'  anemia."  The  devel- 
opment of  this  parasite  seems  to  be  favored  by  wet,  marshy 
soil.  In  appearance  the  parasite  is  whitish  or  brownish  in 
color,  and  in  shape  it  is  cylindrical,  with  more  or  less  pointed 
ends.  It  measures  from  6  to  i8  mm.  long  and  about  i  mm. 
in  thickness.  The  male  has  a  bell-like  expansion  at  its 
posterior  extremity.  It  attaches  itself,  as  said,  to  the  mucous 
membrane  of  the  duodenum  and  upper  jejunum,  by  means 
of  a  set  of  tooth-like  hooks  with  which  the  mouth  is  pro- 
vided. The  eggs  of  this  parasite  are  ejected  with  the  feces, 
and  probably  undergo  further  development  when  favorable 
conditions,  such  as  soil-moisture,  high  temperature,  and  free 
access  to  air,  exist. 

Infection  probably  occurs  through  the  drinking  of  water 
from  marshy  soils  on  which  the  eggs  are  deposited  with  the 
feces  of  individuals  in  whom  the  entozoon  is  present,  or  in 
some  one  or  another  of  the  manifold  ways  that  are  open  to 
men  working  in  and  upon  such  infected  areas.  It  is  almost 
exclusively  seen  in  persons  whose  occupations  bring  them  in 
contact  with  earth,  as  the  various  synonyms  of  the  disease 
imply. 

It  is  obvious  that  the  precautions  to  be  taken  to  prevent 
infection  and  dissemination  are  to  drink  only  boiled  or  fil- 
ls 


226  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

tered  water,  pay  particular  attention  to  personal  cleanliness, 
especially  of  the  hands,  and  to  disinfect  carefully  the  stools 
from  all  individuals  in  whom  the  parasite  is  present. 

Rhabdonema  Intestinale.  —  Frequently  associated  with 
ank)-lostoma  duodenale  is  the  nematode  rliabdoncma  intes- 
tinale, the  parasite  that  is  concerned  in  the  causation  of  the 
so-called  "  diarrhea  of  Cochin  China." 

The  lodgement  of  the  female  worm,  which  is  about  2  mm. 
long  and  hardly  thicker  than  a  hair,  in  the  intestinal  tract  is 
quickly  followed  by  a  brood  of  embryos  that  are  hatched 
from  eggs  in  the  canal.  The  embryos  bear  some  resem- 
blance to  those  of  ankylostoma,  but  differ  from  them  in 
being  hatched  while  in  the  human  host. 

The  presence  of  this  parasite  in  large  numbers  is  account- 
able for  a  persistent  diarrhea  so  often  observed  in  Cochin 
China,  Brazil,  West  Indies,  Egypt,  Ceylon,  Italy,  and  other 
tropical  countries. 

In  marked  cases  of  the  disease  the  daily  extrusion  of  the 
worms,  which  accumulate  in  all  parts  of  the  intestinal  canal, 
is  said  to  reach  enormous  numbers,  having  been  estimated  at 
100,000. 

The  disease  is  contracted  in  the  same  way  as  is  anky- 
lostomiasis, and  the  precautions  that  are  recommended  to  be 
taken  against  the  one  serve  equally  well  against  invasion  by 
the  other  parasite. 

Dracunculus  medinensis  (^filarici  medinensis,  or  Guinea- 
worm)  productive  of  the  condition  known  as  draeontiasis. 

This  is  a  nematode  which  in  the  mature  form  may  meas- 
ure from  60  to  80  centimeters  (24-30  inches)  in  length 
and  from  0.8  to  2  mm.  (0.03-0.08  inch)  in  thickness.  It 
enters  the  body,  most  probably  by  the  mouth,  as  an 
embryo  or  larva  contained  in  the  body  of  the  fresh-water 
flea,  Cyclops.  On  reaching  the  stomach  the  enveloping 
-Structures  are  digested  and  the  embiyo  liberated.  Rapid 
development  now  begins,  and  on  reaching  sexual  ma- 
turity the  adult  worms  proceed  to  reproduce.  After  im- 
pregnation the  female  wanders  from  the  alimentary  tract 
toward  the   subcutaneous   tissues,  where   she   remains  for  a 


DISEASES  DUE    TO   ANLMAL   PARASITES.  22/ 

time  until  she  finally  breaks  through  the  skin,  causing  a 
point  of  ulceration  or  abscess-formation.  The  male  worm 
disappears  after  having  performed  his  function  of  fecunda- 
tion. On  being  discharged  from  the  body,  either  by  the 
breaking  of  an  abscess  or  through  the  open  surface  of  an 
ulcer  that  results  from  her  presence  in  the  subcutaneous  tis- 
sues, the  female  worm  is  literally  packed  with  living  embryos. 
These  find  their  way  into  water  and,  as  stated,  find  in  the 
Cyclops  an  intermediate  host  favorable  to  their  perpetua- 
tion. 

The  disease  dracontiasis,  or,  as  it  is  commonly  called, 
Guinea-worm  disease,  and  the  parasite  causing  it,  have  been 
known  for  a  very  long  time.  Historians  tell  us  that  there 
are  rehable  records  of  it  dating  as  far  back  as  150  b.  c. 
Indeed,  the  reference  made  in  the  fourth  book  of  Moses 
(Numbers,  Chap,  xxi,  verse  6)  to  "  the  fieiy  serpents  "  with 
which  the  children  of  Israel  were  affected  during  their  forty 
years'  wandering  in  the  wilderness  has  been  interpreted  as 
relating  to  this  parasite. 

The  Guinea-worm  is  encountered  in  many  parts  of  the 
Orient ;  on  the  west  coast  of  Africa ;  in  southern  America, 
particularly  Guiana,  Brazil,  and  certain  of  the  islands  of  the 
Spanish-American  group.  Occasionally  dracontiasis  is  seen 
in  this  country,  but  it  is  usually  imported,  though  a  case  is 
reported  by  van  Harlingen  in  a  man  who  had  never  lived 
outside  of  Philadelphia. 

It  is  interesting  to  note  that  in  the  majority  of  cases  of  this 
disease  the  parasite  is  detected,  as  a  rule,  in  a  locality  as  far 
removed  as  possible  from  the  point  of  entrance  into  the  body. 
Thus,  for  example,  of  712  reported  cases  of  the  disease  that 
have  been  compiled  by  Hirsch,  the  parasite  broke  through 
the  skin  of  the  foot  or  lower  part  of  the  leg  in  641   cases. 

From  what  has  been  said  it  is  obvious  that  the  measures 
to  be  taken  against  contracting  and  disseminating  the  disease 
are  to  drink  only  boiled  water  when  in  neighborhoods  where 
the  parasite  is  indigenous,  and  to  burn  the  worm  and  dress- 
ings from  the  ulcer  or  abscess  as  soon  as  removed. 

Filaria  Sanguinis  Hominis  {Filariasis). — Under  this  head 


228  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

reference  is  made  to  a  nematode  encountered  in  the  tropics — 
especially  in  Brazil,  Central  America,  Egypt,  India,  and 
China — that  invades  the  human  body  and  is  associated  with 
chyluria,  hematochyluria,  and  elephantiasis. 

The  life  history  of  this  parasite,  for  much  of  our  knowledge 
of  which  we  are  indebted  to  the  studies  of  Patrick  Manson, 
of  Brisbane,  is,  like  the  filaria  medinensis  and  other  filariae, 
not  completed  in  a  single  host. 

The  embryonic  filarise  probably  gain  access  to  the  body 
through  the  drinking  of  stagnant  or  polluted  water  in  which 
they  have  been  deposited  by  the  mosquito,  now  regarded  as 
the  intermediate  host. 

Upon  entry  into  the  alimentary  canal  the  young  filariae 
bore  through  the  mucous  membrane  and  take  up  their  abode 
in  the  deeper  lymphatics.  When  mature,  the  female  worm, 
which  is,  according  to  Manson,  about  3  inches  long  and 
about  YTo  irich  in  thickness,  is  seen  to  be  packed  with  em- 
bryos in  all  stages  of  development.  These  wander  from  the 
parent  into  the  circulating  blood  and  appear  as  tiny,  actively 
moving,  almost  homogeneous  worms  that  are  readily  detected 
by  their  lashing  movement  when  a  drop  of  blood  containing 


Fir;.  26. — Filaria  sanguinis  hominis  nocturna.     Magnified  about  200  diameters, 
showing  relative  size  to  the  corpuscles  of  the  blood 

them  is  examined  under  the  microscope  (see  Fig.  26).  They 
are  about  37--^,^  inch  in  diameter  and  from  -^-^  to  -^  inch  in 
length.'     At  this  point  their  development  in  man  cea.ses,  and 

'  See  illustrated  paper  by  Henry  :    Trans.  Assoc,  .liii.  Phys.,  1896,  vol.  xi., 
page  96. 


DISEASES  DUE    TO  ANIMAL   PARASITES.  229 

can  only  progress  further  by  the  intervention  of  another  ani- 
mal that  serves  as  an  intermediate  host.  This,  Manson  be- 
lieves, is  the  mosquito,  which  in  sucking  the  blood  from  an 
infected  person  takes  up  the  embryo  filarise,  to  deposit  them 
subsequently  in  water,  from  which  the  cycle  here  outlined 
may  be  repeated.  One  of  the  most  interesting  features  of 
this  nematode  is  the  periodicity  of  its  excursions  from  the 
parent,  or  from  the  deeper  lymphatics  into  the  more  super- 
ficial blood-channels,  and  owing  to  variations  in  this  respect 
three  different  filariae  sanguinis  hominis  are  recognized — viz., 
f.  s.  h.  noctiima — /.  e.,  those  that  are  to  be  found  in  the  super- 
ficial blood-vessels  only  during  the  sleeping  hours  at  night ; 
f.  s.  h.  dhirna — /.  c,  those  found  in  the  circulating  blood  only 
during  the  day  ;  and  /  s.  Ji.  perstans — /.  c,  those  that  persist 
in  the  circulating  blood  throughout  the  twenty-four  hours. 

The  interesting  experiment  of  Mackenzie  demonstrated 
that  with  at  least  one  of  these  varieties — namely,  /.  s.  h. 
nocturiia — its  habits  vary  with  the  habits  of  the  individual 
in  whom  it  is  present.  That  is  to  say,  they  can  be  made  to 
appear  during  the  day  and  disappear  during  the  night,  by 
having  the  patient  sleep  during  the  day  and  remain  awake 
during  the  night  hours,  just  the  reverse  of  their  habits  under 
normal  conditions  of  waking  and  sleeping. 

This  parasite,  as  stated,  is  indigenous  to  several  localities 
in  the  tropics.  A  sufficient  number  of  cases  have  been 
reported  in  the  United  States,  however,  to  justify  the  opin- 
ion that  it  must  be  regarded  as  a  parasite  that  occasionally 
makes  its  appearance  in  the  southern  and  middle  States  of 
this  country,  even  in  individuals  who  have  not  resided  out  of 
these  localities. 

The  clinical  phenomena  observed  in  individuals  infected 
with  this  parasite  are  chyluria,  hematochyluria,  and  ele- 
phantiasis, especially  of  the  scrotum.  From  time  to  time 
persons  are  encountered  who  are  serving  as  hosts  for  this 
parasite,  who  are  apparently  in  health  and  who  evince  no 
external  evidence  whatever  of  its  presence,  beyond  the  pass- 
age of  chylous  urine. 

The    chylous   and   hematochylous    urine  and  the  lymph- 


2:;0 


IIYGIEXE    OF    TRANSMISSIBLE   DISEASES. 


scrotum  are  apparently  the  result  of  obstruction  of  lym- 
phatic vessels  either  by  the  adult  worm  or  by  numbers  of 
the  embryos. 

Trichina  Spiralis  (^Trichinosis). — Within  the  muscles  of 
animals  infected  with  this  parasite  are  to  be  seen  tiny,  opaque 
oval  crystals  measuring  from  0.3-0.4  mm.  (0.01-0.015  inch) 
in  length  and  0.12-0. 15   mm.  (0.005-0.006  inch)  in  breadth, 


Fig.  27. — Trichina  spiralis  in  muscle  (under  low  magnifying  power). 

in  which  are  spirally  coiled,  very  small  worms  that  can  only 
be  detected  with  the  microscope  (Figs.  27  and  28). 

These   bodies    represent  the  embryonic  stage  of  trichina 
spiralis.     When  swallowed  the  enveloping  cyst  is  digested 


Fig.  28. — Trichina  spiralis  in  muscle:  a,  in  the  early  stages;  b,  capsule  calcified 
(after  Leuckart). 

and  the  embryo  liberated.  It  at  once  begins  to  develop  and 
reaches  sexual  maturity  in  the  intestinal  canal  after  from  five  to 
.six  days.  It  is  then  white,  of  about  the  thickness  of  a  hair  and 
approximately  3  mm.  (o.  1 2  inch)  in  length.  The  male  worm, 
which  is  the  shorter  of  the  two,  measures  from  1.5  to  2  mm. 
(0.06-0.08  inch)  in  length. 

With  sexual  maturity  the  female  worm  begins  to  procreate 


DISEASES  DUE    TO  ANIMAL   PARASITES.  23 1 

her  species,  giving  off  from  1000  to  1500  embryos  as  a  brood, 
which  at  once  begin  to  pass  through  the  intestinal  walls  into 
the  general  musculature  by  way  of  the  lymphatic  channels. 
They  penetrate  the  primitive  muscular  fibers,  light  up  a  lim- 
ited inflammatory  reaction,  and  become  encysted.  The  cyst- 
wall  or  capsule  gradually  thickens  and  finally,  in  from  six 
weeks  to  two  months,  becomes  calcified  (see  Fig.  28,  E).  In 
this  condition  they  appear  as  opaque,  whitish,  lens-shaped 
bodies  lying  among  the   muscle-fibers. 

In  the  encapsulated  condition  the  embryo  may  lie  dormant 
in  the  muscles  for  a  long  time,  "  as  long  as  twenty-five  years 
after  their  entrance  into  the  system." 

It  is  of  importance  to  remember  that  of  the  domestic  ani- 
mals whose  flesh  is  used  for  food,  the  hog  is  the  one  by  far 
the  most  frequently  affected  with  this  parasite,  though  it  has 
occasionally  been  observed  in  the  calf  and  sheep  (see  Fig.  29). 


F:it 


Man 


Ho 
Fig.  29. — Life  cycle  and  intermediate  hosts  of  trichina  spiralis  (after  Bollinger). 

While  the  presence  of  trichin?e  in  the  muscles  of  hogs 
causes  apparently  little  inconvenience  to  the  animal,  their 
dissemination  through  the  body  of  man  in  the  disease  trichi- 
nosis is  followed  by  marked  constitutional  disturbances  and 
not  infrequently  by  death. 

During  the  period  in  which  the  worm  is  confined  to  the 
intestinal  canal  the  symptoms  observed  in  man  may  be  prac- 
tically null  in  some  cases.  In  others  loss  of  appetite,  diar- 
rhea, and  vomiting  may  occur.  With  the  emigration  of  the 
embryos  from  the  intestine  to  the  muscles  there  appear  fever, 


232  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

depression,  severe  pain,  and  edema  in  and  about  groups  of 
affected  muscles.  Involvement  of  the  diaphragm,  intercostal 
muscles,  and  those  of  the  larynx  causes  distressing  dyspnea 
that  may  prove  fatal. 

This  parasite  is  observed  in  the  flesh  of  hogs,  cats,  rats ; 
less  frequently  in  calves,  sheep,  dogs,  mice,  foxes,  porcupines, 
and  hedgehogs.  Guinea-pigs  and  rabbits  may  be  infected  by 
feeding  them  with  trichinous  flesh. 

They  are  readily  detected,  when  present,  in  thin  bits  of 
muscle,  by  the  use  of  a  magnifying  power  of  from  40  to  60 
diameters.  The  muscles  and  tissues  that  contain  them  in 
greatest  numbers  are  the  tongue,  laryngeal  muscles,  muscles 
of  the  jaw  and  loin,  intercostals,  and  the  lungs.  It  is  espe- 
cially at  the  tendinous  insertion  of  these  muscles  that  they 
congregate  in  greatest  numbers.  The  search  for  them  is 
greatly  facilitated  by  cutting  very  thin  strips  from  the  sus- 
pected muscles,  placing  them  between  two  heavy  glass  slides, 
which  are  to  be  pressed  together  firmly  and  examined  with  a 
power  of  40  to  60  diameters.  Calcified  trichinae  may  be  ren- 
dered transparent  by  treatment  with  dilute  acetic  or  hydro- 
chloric acid. 

Tric'iinae  are  destroyed  by  heat  (above  65°  C.)  in  a  few 
minutes,  by  drying  in  a  short  time,  and  by  pickling  in  about 
two  months.  They  are  not  killed  by  the  ordinary  process 
of  smoking  meat,  and  not  certainly  by  as  low  a  temperature 
as  20°  to  25°  C. 

Infection  occurs,  therefore,  commonly  through  the  inges- 
tion of  raw  meat  or  meat  that  has  not  been  subjected  to  a 
sufficiently  high  temperature  for  a  time  necessary  to  kill  the 
parasite. 

The  ratio  between  trichinous  and  healthy  hogs  slaugh- 
tered at  the  Berlin  abattoir,  between  the  years  1885  and  1895, 
was  .seen  to  vary  annually  from  0.22  per  looo  to  0.88  per 
1000.  During  the  past  few  years  there  has  been  a  gradual 
diminution  in  the  number  of  cases.  Up  to  1884  the  statistics 
compiled  by  Salmon  for  trichinae  among  hogs  showed  the 
disease  to  be  present  in  a  little  over  2  per  cent,  of  American 
swine,  though  official  observations  made  since  that  date  show 


DISEASES  DUE    TO   ANIMAL    PARASITES.  233 

the  disease  to  be  growing  less  common.  Of  1000  hogs  ex- 
amined by  Osier  and  Clements  in  Montreal,  in  1883,  the 
disease  was  present  in  0.4  per  cent. 

Cestodes  {TcsnicE). — Another  group  of  parasites,  the  ces- 
todes  or  tape-worms,  announce  their  presence  in  the  body  by 
mild  constitutional  symptoms,  such  as  nervous  irritability, 
indigestion,  etc.,  but  more  especially  by  the  appearance  in 
the  stools  of  the  affected  individual  of  segments  of  the  adult 
worm. 

There  are  several  varieties  of  cestodes,  the  most  important 
of  which  are  tcBuia  soluivi,  or  pork  tape-worm ;  tcenia  sagi- 
naia,  or  bovine  tape-worm  ;  and  bothriocephalus  latits,  a  tape- 
worm, rare  in  this  country,  that  has  been  observed  in  particu- 
lar species  of  fresh-water  fish,  especially  the  pike.  As  a 
rule,  tape-worms  are  not  dangerous  to  their  host ;  they  are 
readily  eliminated  by  treatment,  and  easily  guarded  against 
by  simple  prophylaxis. 

The  tape-worms  may  be  regarded  as  colonies  of  zooids, 
the  individuals  of  which  are  strung  together  in  single  file, 
which  gives  to  them  the  appearance  of  a  bit  of  tape.  The 
head  is  simply  one  of  the  group  of  zooids  that  is  provided 
with  either  suckers  or  booklets,  which  enable  it  to  make  fast 
to  some  portion  of  the  intestine,  and  thus  support  from  this 
fixed  point  the  entire  organism.  The  zooids  or  proglottides 
— /.  e.,  the  segments  of  a  tape-worm — are  so  constructed  that 
they  may  each  be  regarded  as  a  sexually  complete  organism. 

A  fully  developed  tape-worm  ordinarily  consists  of  about 
1000  proglottides,  which  are  computed  to  give  birth  annu- 
ally to  approximately  1 20,000,000  eggs,  only  a  very  small 
proportion  of  which,  fortunately,  come  to  maturity. 

Man  becomes  infected  with  these  parasites  by  swallowing 
the  ova  from  ripe  segments  of  the  w^orm.  The  results  of 
swallowing  the  ova  may  be  either  the  development  of  a  sexu- 
ally mature  worm  in  the  intestine,  or  the  permeation  of  the 
muscles  and  viscera  by  the  larva — cysticcrci — that  remain  as 
such  because  of  their  incapacity  to  advance  to  sexual  matur- 
ity in  these  localities.  In  the  former  case  there  is  little 
danger,  while  in  the  latter  the  conditions  produced  may  or 


234 


HYGIENE    OE  TRANSMISSIBLE  DISEASES. 


may  not  be  serious,  depending  upon  whether  the  cysticerci 
are  deposited  in  important  vital  organs  or  not. 

The  commonest  tape-worms  that  are  found  in  the  intestine 
are  the  pork  tape-worm,  the  beef  tape-worm,  and  the  botluno- 
cepliahis  lahis,  especially  the  former  two ;  while  the  visceral 
manifestations  of  these  parasites  are  usually  due  to  the  per- 
meation of  the  tissues  and  organs  by  the  larva  of  tcenia 
solium — /.  c,  by  the  cysticcrciis  celluloses  and  the  larva  of 
tcenia  ecliinococciis. 

Taenia  Solium  {Pork  Tape-zvorni). — This  parasite  is  less 
common  in  America  than  in  Europe.  It  occurs  in  man  as  a 
result  of  eating  raw  or  imperfectly  cooked  pork,  or  food  con- 
taminated with  the  ova  from  the  mature  worm. 

The  mature  tcBuia  soliinn  measures  about  three  or  four 
meters  in  length,  and  consists  of  about  800  proglottides,  only 


Fk;.  30. — Tnenia  solium  (after  Leuckart). 


about  the  terminal  eighth  of  which  are  sexually  mature.  Its 
head  is  small,  about  the  size  of  a  pin-head,  and  is  provided 
with  four  sucking-disks  and  a  circlet  of  from  twenty-five  to 
twenty-eight  sharp  hooklets,  by  which  it  attaches  itself  to  the 
wall  of  the  intestine  {V'\g.  30). 


DISEASES  DUE    TO   ANIMAL    PARASITES:  235 

The  eggs  of  this  worm  are  expelled  with  the  dejecta  of 
the  affected  person.  They  are  nearly  round,  and  are  encased 
in  a  firm  shell  covered  with  minute  rods.  On  being  extruded 
the  eggs  develop  no  further,  unless,  as  is  most  frequently  the 
case,  they  are  taken  up  by  either  man  or  the  hog.  In  the 
latter  event  the  embryo  passes  into  the  voluntaiy  muscles  of 
the  animal,  and  becomes  metamorphosed  into  the  bladder- 
worm,  or  cysticcrciis  cclliiloscB  (Fig.  31),  there  to  remain  until 


Fig.  31. — Cysticerci  cellulosse  :   i,  2,  3,  developmental  forms  ;  4,  in  muscle  (after 

Leuckart). 

it  ultimately  dies  or  until  it  passes  into  the  stomach  of  man 
with  the  flesh  of  the  animal  that  is  eaten  as  food.  On  reach- 
ing the  stomach  of  man  it  develops  into  a  mature  tape-worm 
identical  to  that  from  which  its  life  cycle  was  begun  (Fig.  32). 
Pork  affected  with  cysticerci  is  commonly  known  as 
"  measled  "  or  "  measly." 

It  occasionally  happens  that,  instead  of  the  development 
of  an  intestinal  worm  after  the  swallowing  of  flesh  containing 
cysticerci  celhilosce,  the  embryos  pass  into  the  muscles  or  vis- 
cera of  man.     In  this  event  he,  equally  with  the  hog,  is  play- 


236 


HYGIENE    OF  TRANSMISSIBLE  DISEASES. 


:Man 


Hog 

("Cyst.  -CeU.) 
Fig.  32. — Life  cycle  and  intermediate  hosts  of  taenia  solium  (after  Bollinger). 

ing  the  part  of  intermediate  host.    Under  these  circumstances 
the  larvae  do  not  come  to  maturity,  but  remain  in  the  muscles 


Fig.  33. — Head  of  t;enia  saginata.     A,  neck  retracted;  Ji,  neck  extended 
(after  Leuckart). 

and  organs,  there  to  cause  little  or  no  inconvenience  ;  or,  when 
very  numerous,  to  give  ri.se  to  more  or  less  grave  symptoms, 
according  to  their  locality. 


DISEASES  DUE    TO   ANIMAL    PARASITES. 


237 


Occasionally  this  accident  occurs  in  persons  already  sup- 
porting a  mature  worm,  the  segments  of  which  are  passed 
into  the  stomach  during  attacks  of  vomiting,  there  to  liberate 
embryos  that  penetrate  into  the  muscles  and  viscera. 

Taenia  Saginata  or  Mediocanellata  {Beef  Tape-worm). — 
This  is  the  largest  tape-worm  encountered  in  man,  being  often 
as  much  as  20  to  25  feet  long  and  consisting  of  from  1000  to 
1500  segments.  The  mature  segments  measure  from  17  to 
20  mm.  (0.7-0.8  inch)  in  length,  and  from  5  to  7  mm.  (0.2- 


FlG.  34. — Cysticerci  bovis.     A,  in  muscle  ;  B,  developmental  form  ;  head 
everted  (Leuckart). 


0.3  inch)  in  breadth.  The  head  is  relatively  larger  than 
that  of  tcBuia  solium;  it  is  provided  with  four  strong, 
prominent  suckers,  but  has  no  booklets  (Fig.  33).  Sexual 
maturity  begins  with  about  the  600th  proglottide.  Each 
mature  segment  is  sexually  complete — /.  e.,  is  provided  with 
both  male  and  female  generative  organs.  Development  is 
so  rapid  that  it  is  said  that  as  many  as  10  fully  mature  pro- 
glottides containing  ova  in  large  numbers  may  be  ejected 
daily.  The  ova  have  not  the  power  of  further  develop- 
ment when  thrown  off  from  the  body,  unless  they  are  taken 
into  the  stomach  of  the  ox  ;  then  the  embryos  pass  into  the 


238  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

voluntaiy  muscles,  to  remain  as  bladder-worms  or  cysticerci 
bozds  (Fig.  34).  Beef  so  infected  is  referred  to  as  "  measled." 
It  is  upon  the  eating  of  such  uncooked  "  measled  beef  "  that 
the  larx-ai  of  tceiiia  sagiiiata  are  introduced  into  the  alimentary 
tract  of  man,  there  to  develop  into  the  mature  worm  above 
described  (Fig.  35).  The  worm  in  beginning  its  growth  at- 
taches itself  high  up  on  the  wall  of  the  small  Intestine. 


Fig.  35. — Life  cycle  of  taenia  saginata  (after  Bollinger). 

About  two  to  three  months  intervene  between  the  time  of 
ingestion  of  the  larvae  of  this  worm  and  the  appearance  of 
proglottides  in  the  dejecta. 

Tcenia  saginata  is  commoner  in  this  country  than  is  tcBiiia 
solium,  probably  owing  to  the  greater  care  that  is  given  to 
the  cooking  of  pork. 

Bothriocephalus  latus,  a  large,  long  cestode  found  more 
commonly  in  those  whose  diet  is  composed  of  fresh  fish.  It 
is  said  to  be  common  in  the  Baltic  provinces  and  in  parts  of 
Switzerland.  In  its  larval  form  it  is  often  encountered  in  the 
abdominal  cavity  of  the  pike,  its  intermediate  host,  into  which 
the  embryos  are  believed  to  have  penetrated  from  without. 

The  adult  worm  is  long,  measuring  from  8  to  9  meters ;  is 
thin  at  its  edges,  with  a  central  longitudinal  ridge ;  and  may 
be  composed  of  as  many  as  3000  to  3500  segments.  Its  head, 
about  2  mm.  (0.08  inch)  long,  is  more  or  less  conical ;  is  with- 
out hooklets  ;  and  is  marked  on  either  side  by  a  longitudinally 
grooved  sucker  (Fig.  36  B).     The  embiyo  is  ciliated,  is  pro- 


DISEASES  DUE    TO  ANIMAL    PARASITES.  239 


Fig.  36. — A,  Tasnia  echinococcus  ,    B,  head  of  bothriocephalus  latus  (after 
Leuckart). 

vided  with  booklets,  and  is  able  to  support  itself  in  water  for 
more  than  a  week. 

Feeding  experiments   upon  man,  cats,  and  dogs  with  the 


Man 


Fish 
(Young, 
sexually 
undifferentiated 
Bothr.) 


Unknown 
Host 
(Plerocercus) 


Fig.  37. — Life  cycle  and  intermediate  hosts  of  bothriocephalus  latus  (after 
Bollinger). 

larvse  of  this  parasite  have  resulted  in  the  appearance  of  the 
adult  worm  in  the  intestine  (Fig.  37). 

Taenia  Echinococcus  {Echinococcus  Honiinis). — Occasion- 


240 


HYGIENE    OF   TRANSMISSIBLE  DISEASES. 


ally  man  serves  as  the  intermediate  host  in  the  life  cycle  of 
this  organism.  The  mature  worm  infests  the  dog,  wolf,  and 
jackal.  It  is  very  small,  measuring  but  about  5  mm.  (0.2 
inch)  in  length,  and  is  composed  of  only  3  or  4  segments,  the 
last  and  largest  of  which  alone  exhibits  all  the  characteristics 
of  sexual  maturity.  Its  head  is  very  small,  is  armed  with  a 
double-row  of  from  30  to  50  heavy  hooklets,  and  is  provided 
with  four  suckers  (Fig.  36,  A). 

The  narrow  neck  merges  into  the  first,  imperfectly  devel- 
oped, segment.  The  second  segment  is  more  markedly 
differentiated,  while  the  third,  mature,  segment  is  seen  to 
contain  numerous  eggs  in  which  may  be   detected  the  six- 

(Ta'n.  Sol.) 


Fig.  38. — Life  cycle  and  intermediate  hosts  of  taenia  echinococcus  (after  Bollinger). 

hooked  embryos.  For  the  further  development  of  the 
embryos  after  the  escape  of  the  eggs  from  the  body  it  is 
necessary  that  they  enter  the  body  of  some  other  animal — • 
the  hog,  the  ox,  or  man.  Here  it  penetrates  to  the  viscera, 
commonly  the  liver,  and  enters  the  larval  or  cysticercus 
stage  commonly  known  as  hydatid  or  echinococcus  cysts. 
Unlike  the  other  cysticerci  mentioned,  these  have  the  power 
while  in  this  larval  stage  of  increasing  both  in  size  and  num- 
ber. The  scolices  seen  within  the  cysts,  and  they  are  often 
numerous,  are  each  the  germ  from  which  a  mature  worm 
can  develop  when  favorable  circumstances  present — i.  c\, 
when  they  gain  access  to  the  stomach  of  the  dog  (Fig.  38). 
The  commonest  and  practically  the  only  source  from  which 
echinococcus  cysts  are  contracted  in   man  is  the  dog. 


SECTION    III. 

PROPHYLAXIS  IN  GENERAL  AGAINST  INFEC- 
TIOUS DISEASES, 

INCLUDING  VITAL,   CHEMICAL,  AND    PHYSICAL   PROCESSES,  THE 
MANAGEMENT   OF   CONTAGIOUS    DISEASES,    AND   QUARANTINE. 


VITAL  PROCESSES. 

Comprising'  a  consideration  of  Immunity,  Natural  and  Acquired ;  the 
Practice  of  Vaccination  and  Protective  Inoculation  ;  and  the  Evo- 
lution of  our  Knowledge  of  the  Antitoxic  Condition. 

The  living  animal  body  is  provided  by  nature  with  the 
means  of  combating  more  or  less  successfully  the  inroads  of 
infective  agencies.  Experiment  has  demonstrated  that  there 
resides  within  the  tissues  and  fluids  of  the  healthy  body  the 
property  of  destroying  disease-producing  micro-organisms  in 
large  or  smaller  numbers.  This  function  is  especially  notice- 
able in  the  serum  of  the  circulating  blood,  though  it  may 
also  be  detected  in  other  fluids  and  in  the  juices  from  the 
normal  organs.  In  vigorous  health  it  is  most  manifest,  while 
the  effects  of  malnutrition,  fatigue,  debauch,  disease,  and,  in 
short,  all  influences  that  materially  disturb  the  equilibrium 
of  physiological  function,  are  to  diminish  or  destroy  it  totally. 
On  the  other  hand,  experiment  has  also  shown  that  by  par- 
ticular methods  special  weapons  of  defence  for  use  against 
specific  invaders  may  be  supplied  to  individuals  from  whom 
they  are  normally  absent,  or  be  accentuated  in  their  efficiency 
in  others  in  whom  they  are  present  to  only  a  limited  extent. 
The  practical  procedures  by  which  this  is  accomplished  are 
simple,  though  their  modus  operandi  is  as  yet  far  from  fully 
understood.  They  comprise  those  operations  that  are  con- 
cerned in  the  artificial  induction  of  vital  resistance  to  particu- 

16  241 


242  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

lar  forms  of  disease,  such  as  vaccination,  protective  inocula- 
tion, and  the  other  methods  of  affording  immunity  that  are 
herein  to  be  mentioned. 

In  the  famihar  observation  that  a  single  non-fatal  attack 
of  certain  diseases  often  endows  the  individual  with  immunity 
from  subsequent  inroads  of  the  same  malady,  we  have  the 
starting  point  for  all  that  has  been  done  in  the  important 
field  of  preventive  inoculation. 

This  is  not  by  any  means  an  observation  of  recent  date. 
Early  in  the  eighteenth  century  it  was  the  custom  in  certain 
parts  of  the  Orient  to  induce  small-pox  purposely  by  the 
inoculation  of  healthy  individuals  with  the  matters  from 
small-pox  patients.  The  idea  was  that  if  such  an  inoculation 
was  made  from  a  mild  case  of  the  disease,  only  a  mild  attack 
occurred  in  the  person  inoculated,  and  that  with  recovery  he 
was  henceforth  proof  against  the  disease. 

Prior  to  the  introduction  of  vaccination  by  Jenner,  and  for 
a  short  period  afterward,  the  practice  of  inoculation  was  in 
vogue  in  England,  having  been  introduced  into  that  country 
by  Lady  Montague,  who  had  become  familiar  with  its  em- 
ployment in  India.  Though  unquestionably  lives  were  saved 
by  it,  still,  as  Jenner  himself  testifies,  much  suffering  was 
entailed,  many  lives  were  sacrificed,  and  the  disease  was 
often  disseminated  in  a  violent  form  as  a  result  of  the  inocu- 
lation. 

The  first  scientific  advocacy  of  a  method  which  imitates 
nature  in  affording  immunity  to  an  infectious  disease,  and 
the  benefits  of  which  were  not  only  practically  certain,  but 
were  obtained  without  jeopardy  to  life,  was  that  of  Jenner  in 
1798  in  favor  of  vaccination  against  small-pox.  Before  the 
time  of  Jenner's  preventive  vaccinations  against  this  disease 
it  had  been  observed  that  after  recovery  from  a  harmless 
attack  of  an  affection  known  as  cow-pox,  the  individuals  so 
affected  were  henceforth  in  most  cases  insusceptible  to  the 
ravages  of  small-pox. 

For  a  period  of  more  than  half  a  century  after  Jenner's 
discoveries  nothing  was  done  to  aj)i)lythe  principles  involved 
in  small-pox  vaccination  to  the  prevention  of  other  diseases, 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.     243 

largely,  perhaps,  because  nothing  was  known  as  to  their 
cause,  and  none  of  them  possessed  such  peculiar  relations 
as  had  been  noted  between  small-pox  and  cow-pox. 

With  the  discoveries  made  about  the  middle  of  this  century 
that  certain  infectious  diseases  depended  upon  a  tangible 
cause,  and  the  numerous  additions  to  knowledge  that  rapidly 
accumulated  subsequently,  the  question  of  vital  protection 
again  assumed  a  prominent  place  in  the  minds  of  scientific 
workers. 

The  fact  that  single  attacks  of  the  diseases,  acquired  either 
naturally  or  induced  artificially,  often  protect  the  individual 
against  a  subsequent  attack,  naturally  suggested  the  query 
respecting  the  cause  of  the  phenomenon.  Though  this 
problem  is  still  under  discussion  and  is  still  far  from  com- 
pletely solved,  yet  the  manifold  investigations  of  recent  years 
upon  the  various  phases  of  this  many-sided  subject  have 
been  most  fruitful.  By  exact  experimental  methods  many 
hitherto  obscure  points  have  been  elucidated ;  and  though 
much  remains  to  be  done,  we  can,  nevertheless,  speak  with 
a  fair  degree  of  confidence  upon  many  of  the  important 
features  of  the  subject. 

In  the  early  studies  in  this  field  the  ideas  that  were 
advanced  in  explanation  of  immunity  and  susceptibility 
belonged  largely  to  the  realm  of  the  hypothetical.  They 
were  without  foundation  in  truth  and  when  tried  in  the  bal- 
ance of  experimental  test  were  found  to  be  sadly  wanting. 
From  the  time  of  Jenner's  demonstration,  in  1798,  to  the 
effect  that  it  was  possible  to  protect  human  beings  against 
small-pox  by  vaccination  with  the  lymph  obtained  from  the 
cow-pox  vesicle — a  phenomenon  of  the  intimate  nature  of 
which  we  know  little  more  now  than  he  did  then — up  to 
1880,  nothing  was  contributed  to  our  knowledge  of  the  sub- 
ject. In  1880,  in  the  course  of  his  studies  upon  the  cholera 
of  chickens,  Pasteur^  showed,  for  the  first  time,  that  by  arti- 
ficial means  it  was  possible  so  to  modify  the  virulence  of  the 
bacteria  causing  this  disease  that  they  would  no  longer  pro- 
duce  fatal    results,  but,   instead,   only  temporary  local   dis- 

^  Coftiptes  rendus,  Acad,  des  Sci.,  1880,  tome  xci.,  p.  673. 


244  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

turbances,  and  that  in  these  cases  the  chickens  that  had 
recovered  from  such  a  modified  attack  were  not  now  sus- 
ceptible to  the  inroads  of  the  highly  virulent  bacteria  that 
cause  the  fatal  form  of  the  infection. 

In  view  of  the  fact  that  about  the  same  date  (1878-81) 
Pasteur,  Koch,  Toussaint,  and  others  had  proved  the  rod- 
shaped  organisms  discovered  by  Pollender  (1855)  and  by 
Davaine  (1863)  in  the  blood  of  animals  dead  of  anthrax  to 
be  the  etiological  factors  concerned  in  this  disease,  it  is  not 
surprising  to  find  the  observations  of  Pasteur  utilized  in  a 
scheme  for  the  production  of  a  vaccine  against  this  much 
dreaded  disease,  and  as  a  result  of  numerous  trials  by  differ- 
ent experimenters,  it  was  ultimately  demonstrated  that  by 
the  employment  of  various  agencies,  thermal  and  chemical, 
drying  and  prolonged  cultivation  under  particular  artificial 
conditions,  it  was  possible  to  do  to  the  virulent  anthrax 
bacillus  just  what  Pasteur  had  done  to  the  bacillus  of  chicken 
cholera — namely,  to  so  attenuate  its  virulence  that  it  no 
longer  killed  susceptible  animals,  but  caused  instead  only 
temporary  disturbances  from  which  the  animals  recovered. 
With  recovery  they  were  usually  found  to  be  no  longer 
susceptible  to  the  more  severe,  commonly  fatal,  form  of  the 
infection.  We  can  justly  say  that  it  was  in  the  course  of 
these  studies  on  anthrax  that  the  foundation  stones  were  laid 
for  our  knowledge  of  protective  vaccination  with  attenuated 
living  virus. 

Living  vaccines  capable  of  protecting  animals  more  or  less 
completely  against  fatal  infections  have  from  time  to  time 
been  prepared  by  subjecting  the  virulent  organisms  that 
cause  the  disease  to  a  variety  of  detrimental  agencies — 
namely,  by  exposing  them  to  the  unfavorable  conditions 
that  are  active  in  the  body  of  an  insusceptible  animal ;  by 
cultivating  them  under  artificial  circumstances  in  nutritive 
media  containing  various  hurtful  chemical  agents  in  such 
strength  as  not  to  kill,  but  rather  to  interfere  only  with  the 
full  development  of  their  normal  physiological  functions ; 
by  cultivating  them  in  normal  nutritive  media,  but  at  a  tem- 
perature somewhat  higher  than  that  which  is  compatible  with 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.     245 

vigorous  growth ;  by  subjecting  them  for  a  short  time  to  a 
temperature  that  would  prove  fatal  if  its  action  were  long 
continued ;  by  drying ;  by  exposure  to  direct  sunlight,  to 
electricity,  to  high  pressure,  and  in  short,  by  any  of  the 
manifold  deleterious  influences  that  may  be  so  regulated  as 
to  retard  development  without  actually  destroying  the  organ- 
ism. 

Living  vaccines,  prepared  by  some  one  or  other  of  the 
foregoing  procedures,  have  been  employed  experimentally 
and  in  practice  with  varying  degrees  of  success  for  the  pur- 
pose of  protecting  animals,  and  in  two  instances  man,  against 
a  number  of  infectious  diseases,  notably  anthrax,  sympto- 
matic anthrax,  swine  erysipelas,  pleuropneumonia,  diphtheria, 
glanders,  pneumococcus  infection,  Asiatic  cholera,  and  rabies 
(the  last  two  in  man  also).  In  no  instance  has  their  use  been 
as  general  or  the  results  as  satisfactory  as  in  the  case  of 
anthrax. 

Of  fundamental  importance  to  our  understanding  of  the 
processes  of  immunity  is  the  fact  that  the  constitutional 
symptoms  and  pathological  lesions  of  disease  are  the  results 
of  the  toxic  activities  of  metabolic  products  of  the  bacteria 
concerned  in  the  production  of  disease,  and  that  immunity,  as 
well  as  disease,  is  established  by  these  substances,  not  alone 
when  elaborated  within  the  tissues  of  the  animal  to  which  the 
bacteria  have  gained  access,  but  also  when  they  are  produced 
under  artificial  conditions  of  cultivation  and  purposely  intro- 
duced into  susceptible  animals. 

An  advance  of  great  importance  was  made  in  our  knowl- 
edge of  immunity  through  the  application  of  this  fact  by 
Salmon  and  Smith.^  They  demonstrated  that  a  certain  sort 
of  immunity  to  particular  forms  of  infection  might  be  con- 
ferred upon  animals  by  injecting  into  them  the  filtered,  germ- 
free  products  of  growth  of  certain  bacteria  to  the  pathogenic 
influences  of  which  the  species  of  animal  under  treatment  was 
highly  susceptible. 

'^  Proc.  Biolog.  Soc,  Washington,  D.  C. ,  1886,  vol.  iii.  ;  Centralbl.  filr 
Bakt.  zind  Parasitenkunde,  1887,  Bd.  ii.  ;  Trans.  IX.  Internat.  Med.  Con- 
gress, Washington  1887. 


246  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

This  demonstration  of  the  possibility  of  inducing  immunity 
through  purely  chemical,  or  biologico-chemical,  means  shed 
an  entirely  new  light  on  the  subject.  As  a  result  of  numer- 
ous investigations  suggested  by  this  discovery,  immunity  is 
to-day  held  by  a  number  of  those  who  have  had  most  to  do 
with  the  elaboration  of  our  knowledge  of  it  as  a  purely 
chemical  phenomenon,  a  phenomenon  that  involves  not  the 
micro-organisms  themselves  that  are  concerned  in  the  pro- 
duction of  disease,  but  rather  the  agencies  through  which  they 
produce  it — namely,  their  poisons. 

It  was  subsequently  demonstrated  that  if  the  poisonous 
products  of  growth  of  certain  pathogenic  bacteria  be  intro- 
duced into  the  body  of  a  susceptible  animal  in  non-fatal  doses, 
or  in  a  condition  of  diminished  toxicity,  that  the  effect  of  such 
treatment  is  exhibited  by  a  more  or  less  pronounced  consti- 
tutional reaction  on  the  part  of  the  animal.  After  recovery 
from  this  temporary  disturbance,  the  animal  is  often  found  to 
be  not  only  insusceptible  to  infection  by  the  bacteria  by  which 
the  poison  was  manufactured,  but  the  serum  of  its  blood  in 
certain  cases  has  undergone  a  demonstrable  change :  It  has 
acquired  the  property  of  neutralizing  the  fully  virulent  pois- 
ons, though  its  property  of  destroying  the  bacteria  them- 
selves may  not  in  all  cases  have  been  conspicuously  altered. 
In  other  words,  in  the  process  of  acquiring  immunity  the 
chemical  composition  of  the  blood  is  modified  ;  it  is  enriched 
by  the  addition  to  it,  through  changes  in  the  body,  of  a  sub- 
stance that  is  antidotal  to  the  poisonous  products  of  the  patho- 
genic bacteria  against  which  the  animal  is  immunized,  with- 
out its  relation  to  the  bacteria  themselves  having  been  in  all 
cases  materially  changed. 

In  this  connection  it  is  important  to  note  that  it  is  possible 
by  the  repeated  injections  of  non-fatal  but  gradually  increas- 
ing doses  of  toxins  into  susceptible  animals  to  increase  finally 
the  antitoxic  value  of  the  blood  of  that  animal  to  a  degree 
far  in  excess  of  that  ever  seen  to  exist  in  immunity  acquired 
through  an  ordinary  attack  of  disease,  or  the  immunity  that 
is  induced  simply  as  a  prevention  against  bacterial  invasion. 
It  is  in  this  way  that  antitoxic  serums  are  obtained  that  are 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.    247 

of  sufficient  strength — that  is,  contain  sufficient  amount  of 
the  antidote,  to  be  of  service  in  the  treatment  of  disease 
already  in  progress,  a  condition  necessitating  the  neutraliza- 
tion of  large  amounts  of  poison  circulating  in  the  body  as 
speedily  as  possible  with  the  greatest  amount  of  antidote 
concentrated  in  the  smallest  bulk  of  the  curative  agent. 

In  the  course  of  earlier  investigations  upon  the  subject, 
Buchner  ^  offered  the  suggestion  that  the  immunity  conferred 
by  a  single  attack  of  disease  exists  by  reason  of  certain  "  re- 
active changes''  that  occur  in  the  tissues  during  the  disease, 
and  that  with  the  establishment  of  this  alteration  the  animal 
acquires  insusceptibility  to  further  attacks  of  the  same  malady. 
Though  much  has  been  done  on  the  subject  since  this  hy- 
pothesis was  advanced,  we  are  to-day  but  little  nearer  the 
actual  solution  of  the  problem  than  that  which  is  embodied 
in  this  view. 

The  opinion  now  generally  held  is  that  the  tissues  acquire, 
during  the  constitutional  reaction  coincident  with  the  primary 
attack  of  the  disease,  the  property  of  generating  the  anti- 
dotal substance,  though  it  is  also  believed,  especially  by  Buch- 
ner, that  the  antidotal  or  antitoxic  body  is  in  some  cases  the 
poisonous  products  themselves  of  the  bacteria  so  modified 
through  the  reaction  of  the  tissues  that  they  now  possess  pro- 
tective, neutralizing,  or  antitoxic  peculiarities.  On  these  points, 
however,  there  are  diverse  opinions,  and  it  is  as  yet  impossi- 
ble to  speak  with  certainty. 

The  observation  that  the  serum  of  the  blood  of  a  suscep- 
tible animal  could  be  rendered  antidotal  to  certain  bacterial 
poisons  by  the  gradual  introduction  into  the  animal  of  the 
poisons  until  a  condition  of  tolerance  was  reached,  together 
with  the  discovery  that  a  certain  group  of  highly  pathogenic 
bacteria  produce  their  effects  almost,  if  not  entirely,  through 
poisons  that  they  produce  within  the  system,  while  they 
themselves  are  localized  to  some  particular  point  within  or 
upon  the  body,  suggested  a  line  of  experiments  having  for 
their  object  the  practical  application  of  these  observations  to 

^  "  Eine  neue  Theorie  iiber  Erzielung  von  Immunitat  gegen  Infektions- 
krankheiten,"  Muenchen,  1883. 


248         hygiEaXE  of  transmissible  diseases. 

the  treatment  of  disease  resulting  from  the  activities  of  what 
may  be  termed  the  truly  toxic  pathogenic  bacteria.  It  was 
in  the  course  of  these  investigations  that  Behring  and  Kita- 
sato  '  made  the  important  discovery  that  the  serum  of  the 
blood  of  animals  rendered  tolerant  to  certain  bacterial  toxins 
not  only  afforded  protection  to  these  animals  against  the 
poisonous  effects  of  these  substances  through  antidotal  prop- 
erties, but  that  by  the  transference  of  serum  from  this  immu- 
nized animal  to  another  susceptible  animal,  that  immunity 
was  at  once  conferred  upon  the  animal  into  which  such  serum 
had  been  injected.  The  original  observation  was  made  in  the 
course  of  studies  upon  tetanus. 

It  was  not  long,  however,  before  the  principles  upon 
which  this  observation  rested  were  applied  to  the  study  of 
other  forms  of  toxic  infection,  with  the  result  of  placing  in 
our  hands,  through  the  labors  of  Behring  and  his  associates, 
an  agent  whose  favorable  influence  upon  the  course  of  the 
diphtheritic  infection  is  so  pronounced  as  to  justify  the 
opinion  that  with  the  introduction  of  the  antitoxic  serum 
to  the  treatment  of  diphtheria,  an  epoch  was  marked  in 
the  history  of  medicine. 

By  some  the  method  of  inducing  and  transferring  immu- 
nity, as  elaborated  by  Behring  and  his  colleagues,  is  considered 
as  only  the  induction  of  a  condition  of  tolerance  to  chemical 
poisons — i.  e.,  the  rendering  of  an  animal  poison-proof  (Gift- 
fest),  and  not  as  a  protection  to  bacterial  infection.  There  is 
evidence,  however,  to  indicate  that  this  view  is  erroneous, 
and  that  the  method  is  applicable  in  certain  cases  of  true 
infection  that  are  not  characterized  by  marked  toxic  fea- 
tures.^ 

In  the  present  state  of  our  knowledge  it  is  impossible  to 
say  to  what  extent  acquired  immunity  in  human  beings  is 
due  to  the  presence  of  antitoxic  substances  in  the  circulating 
fluids,  or  to  indicate  in  how  far  the  observations  that  have 
been   made  upon  tetanus  and   diphtheria  are  applicable   to 

*  Deutsche  mcd.    Wach.,  1890,  Bd.  xvi.,   S.  1113. 

^  Consult  Kitt :  Centi-albl.  fur  Bakl.  und  Parasitenkundc,  1893,  S.  869  ; 
Lorenz  :   Ibid.,  1893,  S.  357,  and  1894,  S.  278. 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.    249 

other  infections ;  certainly,  in  so  far  as  the  truly  toxic  infec- 
tions are  concerned,  one  is  constrained  to  feel  sanguine  as  to 
the  ultimate  outcome  of  the  further  application  of  the  prin- 
ciples on  which  the  antitoxic  method  of  treatment  is  based. 
As  a  precautionary  measure,  however,  it  may  not  be  amiss  to 
emphasize  the  impropriety  of  generalizing  from  these  single 
instances.  We  must  bear  in  mind  that  the  conclusions 
reached  with  regard  to  tetanus  in  animals,  and  diphtheria  in 
man,  are  the  results  of  observations  having  an  incontestable 
experimental  basis,  without  which  any  pseudoscientific  struct- 
ure that  we  may  rear  through  analogical  reasoning  will, 
sooner  or  later,  totter  and  fall  without  a  moment's  warning. 
The  wider  application  of  these  principles  to  the  treatment  of 
disease  is  only  to  succeed  through  the  establishment  of  a  firm 
basis  of  experimental  proof  for  each  separate  and  distinct 
affection.  From  this  it  is  clear  to  those  who  are  familiar  with 
laboratory  methods  that  there  are  many  obstacles  to  be  over- 
come, some  of  them  in  our  present  position,  almost  insur- 
mountable. The  impossibility  of  faithfully  reproducing  in 
animals  that  we  use  for  experiment  some  of  the  most  impor- 
tant diseases  to  which  human  beings  are  liable,  may  serve  as 
an  example  of  one  of  the  gravest  of  these  difficulties. 

From  what  has  preceded,  we  observe  that  we  must  dis- 
tinguish between  three  principal  methods  of  inducing  immu- 
nity— namely,  by  the  activities  of  living  bacteria  in  the  tis- 
sues— i.  e.,  by  living  vaccines  ;  through  the  introduction  into 
the  body  of  the  germ-free,  poisonous  products  of  bacteria  ; 
and  through  the  introduction  into  susceptible  animals  of  the 
serum  of  the  blood  (and  other  secretions)  from  another  ani- 
mal already  immunized. 

By  either  the  first  or  second  of  these  procedures  the  con- 
dition of  immunity  is  established  only  after  the  lapse  of  the 
time  necessary  for  the  elaboration  of  the  immunizing  sub- 
stances within  the  tissues  ;  whereas,  by  the  last  method  these 
substances  that  have  already  been  prepared  in  the  immunized 
animal  from  which  the  serum  is  obtained  are  transferred  di- 
rectly, and  the  animal  receiving  them  is  at  once  protected ; 


250  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

as  Ehrlich  ^  conceives  it,  one  simply  transfers  the  protecting 
agent  from  one  animal  to  another. 

There  is  a  further  distinction  as  regards  the  results  of  these 
methods  of  procedure.  The  immunity  that  is  induced  through 
vaccination  with  attenuated  living  virus,  or  conferred  by  the 
gradual  introduction  of  toxins  to  the  point  of  tolerance,  simu- 
lates more  closely  in  the  degree  of  its  permanence  the  immu- 
nity usually  conferred  by  a  non-fatal  attack  of  infection  con- 
tracted in  the  ordinary  walks  of  life  than  does  that  produced 
by  the  injection  of  the  serum  of  immunized  animals. 

Ehrlich^  proposes  to  designate  the  more  or  less  permanent 
immunity  frequently  conferred  by  an  attack  of  an  infectious 
disea:se  as  "  active  immunity,"  while  for  the  immunity  that  is 
established  through  the  direct  transference  of  the  immunizing 
agent  from  the  blood  of  one  animal  to  the  tissues  of  another 
he  employs  the  name  "  passive  immunity."  This  designation 
is  not  acceptable  to  all  writers  on  the  subject,  the  objection 
being  that  there  is  not  as  yet  sufficient  proof  that  the  induc- 
tion of  "  passive  immunity  "is  as  simple  a  matter  as  Ehrlich 
conceives  it  to  be.  There  is  some  evidence  in  support  of  the 
idea  that  the  real  immunizing  agent  may  not  be  contained  in 
the  immunizing  serum,  but  that  this  serum  is  only  instru- 
mental in  inducing  the  peculiar  tissue-reaction  that  results  in 
the  formation  of  the  actual  protecting  body. 

Another  point  in  connection  with  this  subject,  on  which 
there  has  been  considerable  controversy,  is  that  concerning 
the  specificity  of  the  relation  between  the  immunity-inducing 
toxins  and  the  antitoxic  substances  elaborated  in  the  body  as 
a  protection  against  them.  By  the  majority  of  investigators 
there  is  believed  to  be  a  specific  antagonism  between  the 
poisons  produced  by  a  given  infectious  micro-organism  and 
the  protective  agent  that  is  present  in  the  body  of  the  animal 
artificially  immunized  against  this  particular  micro-organism. 
Objections  have  been  raised  to  accepting  this  as  a  law,  on  the 
grounds  that  the  serum  of  artificially  immunized  animals  is 

'  Ehrlich  :    Deutsche  vied.    IVoch.,  1898,   Nos.    32-44  ;   Zeil.   f.    Ilyg.  und 

Infcktionskrankhciten,    1S92,    Bd.   xii.,   S.    183; and  Hiibener :  Ibid., 

1894,  Bd.  xviii.,  S.  51.  *  Loc.  cit. 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.    25  I 

sometimes  seen  to  possess  protective  properties,  to  a  limited 
extent,  against  forms  of  infection  or  intoxication  other  than 
that  against  which  the  animal  has  been  protected.  In  this 
connection,  it  must  be  remembered  that  the  nonnal  serum  of 
man,  of  horses,  and  occasionally  of  other  animals,  has  also  at 
times  been  observed  to  possess  similar  ''general"  antitoxic 
peculiarities.  It  may  be  that  the  observations  on  which  are 
based  the  objections  to  the  idea  of  a  specific  relation  between 
particular  toxins  and  their  antitoxins  can  be  explained  through 
this  normally  present,  universal,  so  to  speak,  antidote. 

In  a  number  of  experiments,  antitoxic  properties  of  the 
serum  against  specific  bacterial  poisons  have  been  induced 
through  the  induction  of  tolerance  to  the  poisons  of  bacteria 
of  a  different  species.  This  condition  appears,  however,  to  be 
little  more  than  an  accentuation  of  the  normally  present  pro- 
tective agent  already  referred  to.  It  has  never  been  possible 
to  bring  about  in  this  manner  as  high  or  as  permanent  a  de- 
gree of  immunity  against  a  particular  disease  as  that  which 
can  be  obtained  by  the  use  of  the  specific  micro-organism 
causing  the  disease,  or  the  products  of  its  growth. 

Of  fundamental  importance  in  their  bearing  upon  this  sub- 
ject are  the  remarkable  observations  of  Pfeiffer.^  He  showed 
that  it  was  easily  possible  to  confer  upon  guinea-pigs  a  con- 
dition of  immunity  to  Asiatic  cholera  by  the  repeated  injec- 
tions into  them  of  sterilized  cultures  of  the  organism  causing 
the  disease.  If  upon  the  establishment  of  immunity  he  now 
injected  into  the  peritoneal  cavity  of  these  animals  an  amount 
of  the  living  culture  that  would  otherwise  certainly  prove 
fatal,  not  only  had  this  no  effect,  but  within  a  few  minutes, 
almost  instantly,  there  was  an  -actual  disintegration  of  the 
organisms  injected  that  could  readily  be  followed  with  the 
microscope.  He  demonstrated,  further,  that  this  relation  be- 
tween the  immune  animal  and  the  organisms  against  which  it 
was  protected  was  a  specific  one,  and  that  no  such  disintegra- 
tion occurred  when  other  bacteria  were  injected.  If,  with  the 
cholera  spirillum  other  bacteria  were  injected,  only  the  chol- 

^  Zeit.  f.  Hyg.  unci  Infektionskrankheiten,  Bd.  xviii.,  S.  I  ;  Ibid.,  Bd.  xx., 
S.    iq8. 


252  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

era  spirillum  was  thus  broken  up.  He  showed,  in  addition, 
that  while  the  serum  of  the  blood  of  the  immune  animal  was 
capable  of  conferring  immunity  from  Asiatic  cholera  upon  other 
animals  not  immune,  it  had  no  disintegrating  effect  upon  the 
cholera  spirillum  when  in  contact  with  it  in  the  test-tube,  but 
if  he  injected  into  the  peritoneal  cavity  of  a  non-immunized 
guinea-pig  the  fatal  dose  of  hving  cholera  spirillum,  and  fol- 
lowed this  immediately  by  an  intraperitoneal  injection  of  the 
serum  from  an  immune  animal,  at  once  the  disintegration  of 
the  bacteria  within  the  peritoneal  cavity  was  to  be  detected. 

It  will  be  seen  that  these  investigations  are  of  importance, 
not  alone  as  regards  the  question  of  specificity,  but  also  as 
regards  the  nature  and  origin  of  the  protecting  body,  for  we 
have  here  a  serum  from  an  immune  animal  capable  of  con- 
ferring immunity — capable,  when  injected  into  the  susceptible 
animal,  of  endowing  it  with  the  peculiar  germicidal  function 
noted  in  the  immune  animal  from  which  the  serum  originated, 
but  still,  totally  incapable  of  this  remarkable  bactericidal  activ- 
ity when  tested  outside  the  animal  body.  Manifestly,  the  real 
protective  agent  is  generated  by  the  tissues  as  a  result  of  the 
specific  irritation  of  a  something  contained  in  the  serum. 

Applying  this  principle  in  part  to  certain  other  infectious 
diseases,  it  has  been  shown  that  the  serum  from  cases  of 
typhoid  fever  when  brought  in  contact  with  pure  cultures  of 
the  typhoid  bacillus  outside  the  body  has  the  property  of 
arresting  its  motility  and  causing  the  individual  cells  to 
arrange  themselves  in  clumps,  a  condition  never  seen  in 
normal  cultures  of  this  organism  and  a  condition  that  is 
seen  only  when  typhoid  bacilli  and  typhoid  serum  are  in 
contact.  It  docs  not  occur  when  other  organisms  are  used, 
nor,  so  far  as  experience  goes,  does  it  result  from  the  use  of 
other  serums  with  this  organism. 

We  mu.st  remember,  however,  that  our  knowledge  on  this 
subject  does  not  as  yet  admit  of  the  laying  down  of  hard 
and  fast  laws,  and  it  is  not  unlikely  that  much  of  what  we 
consider  as  sound  to-day  may  to-morrow  prove  to  be  untrust- 
worthy. We  are  in  many  respects  hardly  more  than  on  the 
threshold  of  this  many-sided  subject. 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.    253 

Equal  in  interest  and  importance  to  any  of  the  other  prob- 
lems relating  to  the  question  of  acquired  immunity,  is  that 
concerning  its  transmissibility  from  parent  to  offspring.  Can 
the  condition  of  acquired  immunity  from  particular  infections 
and  intoxications  be  inherited  ? 

While  there  have  arisen  from  time  to  time  examples  that 
serve  to  indicate  the  possibility  of  this  question  being  an- 
swered in  the  affirmative,  we  are  indebted  to  Ehrlich  ^  for  the 
experimental  demonstration  of  the  accuracy  of  these  indica- 
tions. In  the  course  of  a  series  of  studies  upon  the  vegetable 
toxalbumins,  abrin,  ricin,  and  robin,  especially  as  regards 
their  intoxicating  effects  upon  animals,  and  the  methods  of 
inducing  immunity  from  them,  he  demonstrated  the  possibility 
of  easily  inducing  in  white  mice,  normally  markedly  suscep- 
tible to  these  poisons,  a  condition  of  resistance  that  enabled 
them  to  Avithstand  large  multiples  of  the  otherwise  fatal  dose. 
He  likewise  conclusively  demonstrated  that  females  on  whom 
such  immunity  had  been  conferred  transmitted,  through  the 
milk,  to  their  nursing  young,  an  antitoxic  substance  that 
induced  in  them  a  condition  of  body  through  which  they, 
too,  were  enabled  to  resist  the  otherwise  fatal  dose  of  the 
particular  poison  against  which  the  mother  was  immunized. 
This  transmission  of  immunity  appears  to  be  entirely  a  ma- 
ternal function,  the  father,  in  Ehrlich's  experiments,  playing  no 
part  in  the  process. 

From  the  preceding  considerations  of  the  subject  we  see 
that  a  condition  of  immunity  from  certain  forms  of  infection 
may  be  more  or  less  easily  acquired,  and  that,  when  once 
acquired,  it  may  be  in  some  cases  conferred  upon  the  young 
during  the  nursing  period,  through  the  milk  of  the  mother. 
But  there  is  no  positive  proof  that  such  conferrence  occurs 
during  intra-uterine  life. 

In  the  light  of  these  established  facts,  one  might  be  tempted 
to  consider  the  natural  immunity  possessed  by  certain  in- 
dividuals and  species  from  particular  forms  of  disease  as, 
after  all,  an  acquired  trait — acquired  not  as  a  result  of  the 
purposeful  inoculation  of  progenitors  with  modified  virus  or 

^  Loc.  cit. 


254  HYGIENE    OF  TRANSMISSIBLE   DISEASES. 

attenuated  toxins,  but  rather  acquired  through  the  processes 
of  survival  and  hereditary  transmission.  For  instance,  one 
might  argue  that  when  a  given  number  of  individuals  become 
affected  with  the  same  form  of  infection,  those  that  survive 
are  manifestly  not  only  less  susceptible  to  its  inroads  than 
were  those  that  succumbed,  but,  as  we  have  seen,  the  decree 
of  this  insusceptibility  is  further  increased  by  the  attack  of 
the  disease  through  which  they  have  safely  passed.  These 
survivors,  it  might  be  claimed,  transmit  to  their  offspring  not 
only  certain  mental  and  structural  characteristics,  but  physio- 
logical peculiarities  as  well,  among  which  may  be  a  condition 
of  insusceptibility  to  this  particular  form  of  infection  that  has 
been  accentuated  at  the  nursing  period  through  the  protect- 
ing influences  of  the  milk  of  an  immune  mother.  Still,  in 
support  of  this  view  one  might  continue :  the  constant  pres- 
ence in  a  community  of  a  certain  form  of  disease  is  ultimately 
accompanied  by  a  diminution  of  its  virulence  and  a  lower 
degree  of  fatality  from  it  than  is  seen  to  follow  its  first  or  only 
occasional  appearance,  and  that  continuous  exposure,  there- 
fore, of  large  numbers  of  individuals  to  particular  diseases 
may  result,  through  the  natural  phenomena  of  survival  and 
inheritance,  in  developing  a  race  endowed  with  nahiral  iiisus- 
ccptibility  to  this  malady. 

Plausible  and  attractive  as  this  view  may  appear  on  super- 
ficial examination,  there  are  objections  to  its  adoption. 

In  the  strict  sense  of  the  word,  and  in  the  light  of  present 
knowledge,  we  must  regard  natural  immunity  as  a  trait  that 
has  been  transmitted,  and  is  further  transmissible,  through 
generations  by  parents  in  whom  it  is  blastogenic.  It  is  con- 
genital, therefore,  and  inherent  to  the  integral  protoplasm  of 
the  individual  or  species  endowed  with  it.  There  is  no  evi- 
dence of  its  having  been  acquired  through  any  of  the  chan- 
nels that  apply  to  the  acquisition  of  immunity.  Its  trans- 
mission, like  other  physiological  peculiarities,  is  probably  as 
much  under  the  paternal  as  the  maternal  influence,  and  is 
lasting ;  whereas,  the  transmission  of  acquired  immunity  is  a 
function  only  of  the  mother  and,  so  far  as  we  know,  is  of  but 
temporary  du ration. 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.    255 

There  can  be  no  doubt  that  the  constant  exposure  of  a 
race  of  individuals  to  a  disease  ultimately  results  in  a  diminu- 
tion of  susceptibility  of  many  of  the  individuals  to  this  dis- 
ease. It  appears  to  be  more  logical  to  consider  this  condi- 
tion of  "  acclimatization,"  as  it  is  popularly  called,  from  two 
standpoints — namely,  with  regard  to  the  individual,  and  with 
regard  to  the  race.  Where  it  concerns  an  individual  it  is 
either  natural,  in  the  sense  of  the  word  "  natural  "  as  here 
used — i.  c,  an  idioplasmic  characteristic,  or  is  acqinred,  as  a 
result  of  an  attack  of  the  disease  through  which  the  indi- 
vidual has  safely  passed ;  where  it  concerns  a  race  it  appears 
to  be  much  more  likely  that  it  has  evolved  as  a  result  of  the 
survival  and  multiplication  of  those  individuals  of  the  race 
who  were  by  nature — /.  c,  congenital — either  completely  or 
partly  insusceptible,  their  susceptible  fellows  having  gradually 
been  exterminated. 

It  may  be  safely  said  that  probably  no  human  race  is,  as  a 
whole,  immune  from  any  disease  of  man.  Nevertheless,  in 
every  race  there  may  be  encountered  individuals  who  are 
more  or  less  immune  to  this  or  that  disease  ;  and  with  regard 
to  the  relation  of  certain  races  to  particular  diseases  the  pro- 
portion of  such  individuals  may  be  conspicuously  high. 

Still  further  in  favor  of  the  idioplasmic  origin  of  this 
peculiarity  of  natural  imniiinity,  and  in  opposition  to  its 
acquisition  by  exposure  to  disease,  is  the  fact  that  even 
among  these  races  which,  through  constant  exposure  to 
particular  diseases,  have  become  "  acclimated,"  the  newly 
born  do  not  from  birth  partake,  as  a  rule,  of  the  peculiarity, 
and  usually  become  insusceptible  only  after  having  had  the 
disease.  A  striking  illustration  of  this  is  offered  by  the 
Creole  populations  in  yellow-fever  districts.  While  not 
totally  immuned  from  the  disease,  the  Creoles  are,  as  a  race, 
much  less  susceptible  than  their  white  brothers,  and  yet,  on 
the  authority  of  Guiteras,  "  the  foci  of  endemicity  of  yellow 
fever  are  essentially  maintained  by  the  Creole  infant  popula- 
tion." Manifestly,  the  relative  insusceptibility  of  the  Creole 
to  this  disease  is  not  a  race  characteristic,  but  is  rather  one 
that  the  individual  acquires  for  himself  only  with  recovery 


256  HYGIENE    OF  TRANSMISSIBLE   DISEASES. 

from  the  disease.  The  increase  of  tissue-resistance  acquired 
in  this  way  cannot  be  regarded  as  natural  immunity  in  the 
sense  in  which  the  term  is  now  generally  understood. 

To  admit  that  the  condition  of  natural  immunity  repre- 
sents, after  all,  the  inheritance  of  an  induced  peculiarity,  is  to 
admit  in  general  the  possibility  of  the  hereditary  transmission 
of  acquired  traits,  "  an  assumption  that  has  often  been  made, 
but  never  yet  proved."  ^ 

Natural  immunity  must  as  yet  be  considered  as  a  vital 
property,  inherent  to  the  idioplasm,  the  intimate  nature  and 
workings  of  which  cannot  be  explained.  It  distinguishes  the 
individual  endowed  with  it  only  by  its  protective  influences 
during  exposure  to  particular  forms  of  disease.  It  is  not 
explainable  through  any  demonstrable  excess  of  protective 
characteristics  of  the  body-fluids  or  tissues,  contrary  to  what 
may  usually  be  done  in  the  case  of  artificially  immunized 
animals,  for,  as  stated  above,  the  fluids  of  the  body  of  the 
naturally  immune  animal  may  be  neither  more  nor  less 
germicidal  or  antitoxic  than  are  similar  fluids  from  animals 
that  are  naturally  susceptible. 

Manifestly,  the  prevention  and  treatment  of  disease  along 
the  lines  suggested  by  the  investigations  here  cited  in  many 
respects  closely  simulate  some  of  the  methods  of  nature.  It 
is  from  this  standpoint  that  we  believe  the  further  elaboration 
and  wider  application  of  the  principles  involved  in  the  proc- 
esses of  preventive  inoculation  and  serum  therapeutics  are 
destined  to  be  of  inestimable  service  in  the  advancement  of 
the  preventive  and  curative  medicine  of  the  future. 

Already  as  a  result  of  these  labors,  animals  have  been 
rendered  more  or  less  insusceptible  to  a  number  of  different 
infections  and  intoxications — for  instance,  to  chicken  cholera, 
anthrax,  erysipelas,  symptomatic  anthrax,  malignant  edema, 
hog  cholera,  typhoid  fever,  hemorrhagic  septicemia,  vibrionic 
septicemia,  Asiatic  cholera,  diphtheria,  tetanus,  pneumococcus 
infection,  pyocyaneus  infection,  proteus  infection,  infection  or 

'  Weismann,  "Essays  on  Heredity  and  Kindred  Biological  Problems;" 
"Essay  on  Retrogressive  Development  in  Nature,"  vol.  ii.,  p.  14.  Edited  by 
Poulton  and  Shipley,  Oxford,  Clarendon  Press,  1892. 


PROPHYLAXIS  AGAINST  INFECTIOUS  DISEASES.    2$"/ 

intoxication    by    bacillus   coll  coininiinis,   and   infections    by 
pyogenic  cocci. 

Not  only  has  the  possibility  of  conferring  immunity  to  these 
infections  been  demonstrated,  but  in  the  case  of  certain  of 
them  the  serum  of  the  blood  of  the  immunized  animals  has 
been  found  to  possess  properties  that  can  be  utilized  in  the 
treatment  of  these  infections  or  intoxications  after  they  are 
already  in  progress  in  other  animals.  Thus,  for  example,  the 
treatment  of  diphtheria  by  the  antitoxin  method  comes  under 
this  head.  In  the  case  of  erysipelas,  the  experiments  of 
Marmorek  ^  and  others  indicate  similar  possibilities.  Marmorek 
found  in  the  blood  of  rabbits  immunized  from  infection  by 
the  streptococcus  of  erysipelas,  a  substance  that  he  states 
possesses  curative  powers  over  the  disease  when  it  is  already 
in  progress  in  non-immunized  animals.  Pfeiffer  and  Kolle  ^ 
have  detected  in  the  blood  of  animals  rendered  tolerant  to 
the  typhoid  toxin  a  substance  that  is  germicidal  to  the  typhoid 
bacillus,  and  Beumer  and  Peiper^  find  a  non-germicidal,  but 
rather  an  antitoxic  substance  in  the  blood  of  animals  artifici- 
ally immunized  from  the  typhoid  poison.  Beumer  and  Peiper 
state  that  this  serum  possesses  not  only  immunizing  powers, 
but  that  the  poisonous  effects  of  the  typhoid  toxins  can  be 
neutralized  by  the  subsequent  injection  of  the  antitoxic  serum. 
They  believe,  therefore,  that  the  serum  possesses  curative 
virtues.  Yersin,  Borel,  and  Calmette,*  in  their  studies  upon 
bubonic  plague,  obtained  from  the  blood  of  animals  rendered 
immune  from  this  infection  an  actively  antitoxic  serum  that 
they  hope  to  utilize  ultimately  in  the  treatment  of  the  disease. 
The  studies  on  vaccinia  lead  to  the  belief  that  there  exists  in 
the  blood  of  the  vaccinated  animal  a  substance  possessing 
certain  antagonistic  relations  to  the  active  principle  of  vac- 
cine lymph,^  whatever  that  may  be.     In  this  case,  as  with 

^  La  semaine  vied.,  1895,  ^'^o-  '7  !  Annales  de  P Inst.  Pasteur,  1895,  tome 
ix.  ;  consult  also  Roger  :   Ibid. 

^  Deutsche  med.   JVock.,  1894,  No.  48. 

'  Zeit.  f.-  klin.  Med.,  Bd.  xxviii.,  Hefte  3  and  4. 

*  Annales  de  V  Inst.  Pasteur,  1895,  No.  7. 

^  For  literature  on  this  subject  consult  Sternberg  and  Reed :    Trans.  Assoc, 
of  Avier.  Phys.,  1895,  vol.  x.,  p.  57. 
17 


258  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

scarlatina,  both  experiments  and  results  are  unsatisfactory, 
because  of  the  important  unknown  factors  that  come  into 
play.  From  recent  investigations  it  seems  probable  that  the 
treatment  of  tetanus  by  means  of  antitoxic  serum,  as  is 
shown  to  be  possible  in  animals,  will,  before  a  very  great 
while,  be  successfully  extended  to  the  disease  in  men.  The 
treatment  of  Asiatic  cholera  by  the  antitoxin  method  is  ap- 
parently destined  to  be  an  outcome  of  the  very  near  future, 
and  finally,  the  experiments  bearing  upon  the  treatment  of 
tuberculosis  by  means  of  antitoxic  substances  is  predicted  by 
Behring  to  be  soon  successfully  demonstrated.  Behring  and 
Knorr  ^  already  claim  to  have  detected  in  the  blood  of  ani- 
mals rendered  tolerant  to  the  poisonous  influences  of  tuber- 
culin (the  toxin  produced  by  bacillus  tuber adosis),  a  body, 
antituberculin,  that  possesses  the  property  of  robbing  tuber- 
culin of  its  poisonous  peculiarities. 

When  we  contemplate  this  array  of  practical  results  and 
bear  in  mind  that  they  are  the  outgrowth  of  experiments 
made  with  a  definite  purpose,  each  step  of  which  was  directed 
toward  a  particular  object,  and  that  through  these  experi- 
ments susceptible  animals — and,  in  a  few  instances,  man — 
have  been,  and  may  at  will  be,  rendered  more  or  less  immune 
from  a  number  of  diseases  of  bacterial  origin,  there  is  justifica- 
tion for  the  statement  "  that  the  probfems  relating  to  immu- 
nity and  infection  have  been,  in  part  at  least,  removed  from 
the  realm  of  pure  hypothesis  and  placed  in  a  position  favor- 
able to  exact  experimental  solution  "  (Welch). 

'  Behring  :  Address  delivered  before  the  67th  meeting  of  Naturalists,  at 
Lubeck — Deutsche  7ned.   IVocA.,   1895,  No.  38. 


ChEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    259 

CHEMICAL  AND   PHYSICAL   PROPHYLACTIC 
MEASURES. 

We  have  already  learned  that  there  is  thrown  off  from  the 
body  in  the  course  of  transmissible  diseases  substances  which, 
if  not  destroyed,  possess  the  power,  under  favorable  circum- 
stances, of  disseminating  these  maladies.  In  some  instances 
such  infective  agents  are  contained  in  the  secretions  from  the 
mouth,  throat,  and  nose,  as  in  diphtheria  and  whooping 
cough ;  in  others  they  are  present  in  the  matters  spat  up 
from  the  lungs,  as  in  pulmonary  tuberculosis,  influenza,  and 
pneumonia  ;  again,  they  are  present  in  the  vomited  matters 
and  evacuations  from  the  bowels,  as  in  cholera,  typhoid  fever, 
and  tropical  dysentery ;  while  in  still  other  cases  they  are 
discharged  through  lesions  of  the  skin  consequent  upon  sub- 
cutaneous suppurations,  or  from  the  surface  of  the  skin  itself, 
as  during  the  desquamation  period  of  the  acute  exanthemata. 

We  have  also  learned  that  the  majority  and  the  most  im- 
portant of  the  factors  directly  concerned  in  the  causation  of 
specific  communicable  diseases  are  living  micro-organisms — 
bacteria — and  that  as  they  are  expelled  from  the  infected  in- 
dividual they  are  often  associated  with  other  bacterial  species 
that  are  concerned  in  disease-production — /.  e.,  with  the  inno- 
cent varieties  usually  present  in  the  mouth,  the  intestines,  and 
the  skin. 

In  many  instances  these  infective  micro-organisms  find  con- 
ditions outside  the  body  that  are  not  at  once  detrimental  to 
their  vitality  and  pathogenic  activity  ;  indeed,  under  particu- 
lar enviroment  they  are  capable  of  increase  and  multiplica- 
tion and  of  becoming  the  source  from  which  the  disease  may 
be  disseminated  through  large  groups  of  susceptible  individu- 
als. With  the  view  of  preventing  such  accidents  disinfection 
and  isolation  are  practised. 

Disinfection. — Strictly  speaking,  the  term  disinfection 
signifies  the  destruction  of  infective  agents,  but  by  the 
methods  of  disinfection  commonly  in  use,  there  is  no  dis- 
crimination made  between  the  various  species  of  bacteria, 
and  all  living  micro-organisms,  innocent  as  well  as  infective, 


26o  JIYGIENE    OF   TRANSMISSIBLE   DISEASES. 

fall  victim  to  the  germicidal  activity  of  approved  disin- 
fectants. 

The  terms  disinfectant  and  germicide  have,  therefore,  be- 
come synonymous  by  usage,  and  in  this  sense  a  disinfected 
mass  is  one  in  which  all  living  micro-organisms  have  been 
killed. 

It  seems  proper  at  this  place  to  define  the  precise  meaning 
of  several  terms  that  are  used  in  connection  with  the  various 
methods  that  are  employed  against  the  development  of  bac- 
teria and  for  the  suppression  of  their  malodorous  metabolic 
products.  Such  definitions  become  necessary  because  of  the 
frequent  misunderstanding  of  the  meanings  of  the  terms  and 
of  the  principles  involved,  and  because  of  the  confusion  that 
arises  from  their  indiscriminate  and  inaccurate  use.  Briefly 
then,  a  disinfectant  or  germicide  (the  terms  as  stated  are,  by 
usage,  synonymous)  may  be  defined  as  a  substance  that  kills 
bacteria  and  their  spores  ;  an  antiseptic  is  a  substance  that  is 
antagonistic  to  the  growth  of  bacteria  without  of  necessity 
killing  them  ;  while  a  deodorizer  may  be  either  a  disinfectant 
or  an  antiseptic,  or  neither,  but  simply  a  substance  having  the 
power  of  destroying  or  masking  odor,  without  regard  to  either 
destruction  of  the  micro-organisms  that  cause  it  or  the  arrest 
of  their  development. 

In  the  practice  of  disinfection  there  should  be  maintained 
a  tolerably  fixed  relation  between  the  amount  of  a  given  dis- 
infectant used  and  the  mass  of  matter  to  be  disinfected — /.  e., 
the  number  of  bacteria  to  be  killed.  If  this  ratio  be  not 
observed  there  is  either  an  excess  of  disinfectant  or  there  is 
a  scarcity ;  in  the  latter  event  disinfection  is  incomplete. 

The  majority  of  disinfectants  have  the  property  of  prevent- 
ing the  development  of  bacteria,  even  when  employed  in 
solutions  very  much  weaker  than  would  be  necessary  for 
disinfection  ;  that  is,  in  these  smaller  quantities  they  exhibit 
antiseptic  functions.  Many  antiseptics  have  no  disinfectant 
or  germicidal  properties  whatever.  This  is  true  of  many  of 
the  weaker  vegetable  acids,  of  a  number  of  aromatic  bodies, 
of  sugar,  and  of  sodium  chloride. 

When  added  to  un  decomposed  matters  both  disinfectants 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    26 1 

and  antiseptics  prevent  decomposition  and  putrefaction,  and, 
consequently,  the  evolution  of  bad  odors,  but  when  decom- 
position is  well  advanced  there  are  few,  if  any,  of  the  trust- 
worthy disinfectants  that  have  the  property  of  completely 
destroying  bad  odors.  Many  compounds  are  used  for  this 
purpose,  but,  as  a  rule,  their  employment  amounts  to  little 
more  than  the  substitution  of  one  odor  for  another. 

There  are  a  great  many  substances  that  are  possessed  of 
germicidal  properties,  though  the  list  of  those  worthy  of 
confidence,  and  hence  of  those  in  common  use,  is  compara- 
tively small. 

For  convenience  of  description  the  modes  of  disinfection 
here  described  will  be  classified  as  chemical  and  physical. 

Chemical  Disinfection. — By  chemical  disinfection  we  un- 
derstand the  destruction  of  the  vitality  of  living  micro-organ- 
isms, through  the-  use  of  chemical  compounds.  In  its  prac- 
tical application  the  disinfectant  is  mixed  with  or  applied  to 
the  mass  or  article  to  be  disinfected,  in  such  proportions  and 
after  such  a  manner  as  experiment  has  dictated  to  be  most 
favorable  to  the  accomplishment  of  the  desired  result. 

In  many  cases  it  is  not  possible  to  explain  the  inodiis  oper- 
andi of  disinfection,  any  more  than  to  say  that  the  micro- 
organisms are  poisoned  by  the  disinfectant,  though  in  partic- 
ular instances  this  is  accomplished  by  a  union  between  the 
disinfectant  and  the  protoplasm  of  the  bacteria ;  in  others 
there  seems  to  be  a  coagulation  of  the  albuminoid  constit- 
uents of  the  bacteria,  while  in  others  disinfection  succeeds 
through  the  disintegrating  influence  that  the  disinfectant  has 
upon  the  bacteria. 

The  essentials  of  a  useful  and  trustworthy  chemical  disin- 
fectant are  : 

1.  It  shall  be  a  germicide — /.  c,  it  shall  possess  the  property 
of  destroying  bacteria  and  their  spores. 

2.  It  should  be  so  constituted  that  its  germicidal  properties 
are  not  destroyed  by  the  extraneous  matters  in  which  the 
infective  micro-organisms  that  are  to  be  killed  are  located. 

3.  With  ordinary  care  it  should  not  be  dangerous  (directly 
poisonous)  to  those  who  are  to  use  it. 


262  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

4.  It  should,  if  possible,  be  without  disagreeable  odor ;  it 
should  be  cheap  in  price,  easy  to  manipulate,  and  for  particular 
purposes  should  not  cause  permanent  stains  or  be  destructive 
to  the  skin,  to  fabrics,  or  to  other  articles  on  which  it  is  to  be 
employed. 

The  entire  list  of  chemical  preparations  that  possess  more 
or  less  germicidal  properties  is  too  long  to  introduce  in  a 
book  of  this  size.  It  will  suffice  to  mention  only  those  that 
may  be  regarded  as  of  the  greatest  general  usefulness. 

Sulphur  Dioxide  ;  SulpJiurojis-acid  Gas,  SOj. — Until  within 
a  very  short  time  there  was  probably  no  gaseous  disinfectant 
that  was  more  commonly  used,  or  which  enjoyed  a  greater 
degree  of  confidence  than  did  the  fumes  arising  from  the 
combustion  of  sulphur.  Its  principal  employment  has  been 
for  the  fumigation  of  apartments,  wards  of  hospitals,  ship- 
cabins  and  -holds,  etc. 

Modern  investigations  have,  however,  shown  that  the  use- 
fulness of  this  gas  for  the  purpose  of  disinfection  is  compara- 
tively limited.  In  the  dry  state  it  possesses  little  penetration, 
does  not  destroy  spores,  and  is  uncertain  in  its  action  even 
upon  non-spore-forming  organisms.  The  amount  of  it  that 
is  at  all  reliable  should  not  be  less  than  4  per  cent,  by  volume 
of  the  air-capacity  of  the  room,  and  this  should  be  maintained 
for  from  twelve  to  twenty-four  hours — a  condition  very  dif- 
ficult to  meet  when  we  remember  the  practical  impossibility 
of  so  sealing  all  cracks,  pores,  and  openings  of  a  room  as  to 
prevent  diffusion. 

Its  efficiency  is  markedly  increased  when  the  objects  to  be 
disinfected  are  moist,  a  condition  that  may  in  part  be  met  by 
spraying  with  water  or  by  generating  steam  at  the  same  time 
that  the  gas  is  being  evolved.  Upon  moist  objects  its  ger- 
micidal powers  are  comparatively  marked  for  those  micro- 
organisms that  do  not  form  spores,  but  even  here  the  materials 
to  be  disinfected  must  be  freely  exposed  to  its  action. 

In  the  practical  use  of  this  gas  as  a  disinfectant  the  follow- 
ing precautions  are  to  be  observed,  otherwise  its  employment 
is  useless  : 

All  visible  cracks,  crevices,  and  openings  of  the  room  to  be 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    263 

disinfected  should  be  carefully  closed  with  strips  of  adhesive 
paper  or  with  putty.  To  obviate  accidents  from  fire,  while 
the  sulphur  is  burning,  a  tub  half  filled  with  water  should  be 
placed  in  the  center  of  the  room ;  two  bricks  are  to  be  stood 
on  end  in  it,  and  on  the  top  of  these  is  to  rest  the  pan  in  which 
the  sulphur  is  to  be  burned.  Into  the  pan  is  to  be  placed 
sulphur  in  the  proportion  of  3  pounds  to  each  lOOO  cu.  ft.  of 
air-space  in  the  room.  The  objects  in  the  room  are  then  to 
be  moistened  either  by  spraying  with  a  hand-atomizer  con- 
taining water,  or  else  by  condensed  steam  generated  from 
boiling  water.  Finally,  a  little  alcohol  is  poured  over  the 
sulphur  in  the  pan,  lighted,  and  the  door  of  the  room  closed 
and  kept  closed  for  twenty-four  hours.  At  the  end  of  this 
time  doors  and  windows  are  thrown  open  and  the  room  thor- 
oughly aired.  The  danger  from  fire  may  be  eliminated  by 
using  compressed  sulphur  dioxide  instead  of  the  gas  obtained 
by  burning  sulphur.  The  gas  may  be  obtained  from  the 
dealers  in  a  liquefied  state  (liquefied  by  pressure)  in  metal 
cylinders  provided  with  valves  for  its  liberation.  These 
cylinders  may  either  be  placed  in  the  room  and  the  gas 
slowly  liberated,  or  they  may  be  placed  in  an  adjoining 
hallway  or  room  and  the  required  amount  of  gas  conveyed 
into  the  infected  room  by  a  tube  passed  through  the  key- 
hole of  the  door.  After  the  room  has  been  kept  closed 
for  the  necessary  time,  the  usual  cleansing  operations  may 
be  begun.  All  objects,  such  as  pillows,  mattresses,  bundles, 
clothing  in  closets,  chests,  etc.,  should  be  disinfected  by 
steam. 

Chlorine  and  bromine  possess  marked  disinfecting  prop- 
erties. Like  sulphurous-acid  gas,  however,  they  exhibit 
their  highest  germicidal  peculiarities  only  upon  moistened 
objects.  They  are  not  in  general  practical  use,  for  the  reason 
that  they  are  more  or  less  destructive  to  fabrics,  tissues,  etc., 
but  more  especially  because  of  their  very  irritating  and  some- 
times dangerous  action  upon  the  respiratory  apparatus  of 
those  who  are  using  them.  In  the  gaseous  condition  they 
are  not  to  be  recommended  for  general  use. 

Formaldehyde,  Formie  Aldehyde,  Formalin,  etc. — Formal- 


264  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

dehyde,  the  vapor  resulting  from  the  slow  (incomplete)  com- 
bustion of  methyl  alcohol  under  access  of  air,  is  the  aldehyde 
of  formic  acid  ;  or,  in  other  words,  it  is  an  alcohol  of  the 
marsh-gas  (methane)  series  from  which  hydrogen  has  been 
extracted  by  oxidation.  The  position  of  formaldehyde  in  the 
series  of  products  that  result  from  the  oxidation  of  marsh 
gas  is  as  follows  : 

Marsh  Gas,  Methane.        Methyl  Alcohol.        Formaldehyde.        Formic  Acid. 
CH,.  CHp.  CH.p.  Cn.f).,. 

When  formaldehyde  gas  is  dissolved  in  water  to  about 
the  point  of  saturation,  we  have  the  proprietary  solution 
known  commercially  as  formalin.  Formalin  represents 
a  solution  of  formaldehyde  gas  in  water  of  the  strength 
of  from  35  to  40  per  cent,  by  weight.  For  practical  purposes 
of  disinfection  this  body  is  employed  both  in  its  pure  gaseous 
state  as  formaldehyde,  and  in  its  watery  solution  as  formalin. 


Fig.  39. — Lamp  for  jjent-rating  fornialdchydc  from  methyl  alcohol. 

The  active  gas  as  used  for  purposes  of  disinfection  is  obtained 
in  several  ways — viz.,  by  the  slow  combustion  of  methyl  alco- 
hol in  lamps  especially  constructed  for  the  purpose  (sec  Fig. 
39);  by  liberating  it  from  its  watery  solution  under  the  influ- 
ence of  high  temperature,  in  especially  constructed  autoclaves 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    265 

and  generators  (Figs.  40-42) ;  and  by  decomposing  its  solid 
•  polymerized  form  in  open  vessels  through  the  action  of  heat 
(Fig.  41).  The  various  forms  of  apparatus  on  the  market  for 
the  purpose  are  fully  described  in  the  circulars  issued  by 
their  several  makers. 

Since  the    discovery  that  formaldehyde  vapor   possesses 
very  marked  germicidal  properties  it  has  been  subjected  to 


Fig.  40. — Autoclaves  for  generating  formaldehyde  (i)  from  formalin  and  (2) 
from  formochloral :  A,  chamber  for  reception  of  the  fluid ;  both  chambers  are 
hermetically  sealed  when  apparatus  is  in  operation  ;  B,  lamp  for  supplying  heat ; 
C,  tube  for  conducting  gas  from  generator  into  the  room  to  be  disinfected. 

most  careful  study  in  this  connection,  by  a  number  of  com- 
petent investigators  ;  and  though  the  results  have  been  in 
some  respects  discordant  they  agree  in  certain  essential  points 
— viz.,  that  formaldehyde  obtained  by  either  of  the  several 
processes  in  common  use  is  a  gaseous  disinfectant  of  high 


266  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

order  for  the   surfaces  of  rooms  and  for   contained  objects 


Fig.  41. — Apparatus  for  generating  formaldehyde  from  tablets  of  polymerized 
formaldehyde  :  i,  small  form  ;  2,  for  larger  quantities  ;  A  in  each  figure  indicates 
the  cup  in  which  the  tablets  are  placed. 

when  the  latter  are  freely  exposed  to  its  action  ;  that  it  quickly 


Fk;.  42. — Modified  Novy-Waite  formaldehyde  generator :  A,  retort  for  con- 
taining formalin ;  B,  lamp  for  supplying  heat ;  C,  tube  for  conducting  gas  from 
retort  into  room  to  be  disinfected. 


destroys  not  only  the  Icss-rcsistant,  non-sporc-formin^  patho- 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    26/ 

genie  bacteria,  but  the  more  highly-resistant  spore-formers 
and  their  spores  as  well ;  that  to  accomplish  this  end  there 
must  be  a  definite  relation  between  the  gas  used  and  the  space 
to  be  disinfected ;  and  that  the  space  shall  be  so  closed  that 
this  relation  may  be  maintained  for  a  definite  length  of  time. 

Its  powers  of  penetration  cannot  be  relied  upon,  and  when 
used  in  rooms,  hospital  wards,  etc.,  all  articles,  such  as  mat- 
tresses, pillows,  clothing  in  chests,  closets,  trunks,  etc.,  had 
better  be  subsequently  subjected  to  disinfection  by  streaming 
steam. 

The  methods  thus  far  tested  for  the  generation  of  this  gas 
that  have  shown  themselves  to  be  least  trustworthy  are  those 
in  which  methyl  alcohol  is  slowly  burned  in  lamps.  As  a 
rule,  the  lamps  have  been  too  small  and  their  continuous 
combustion  too  uncertain  ;  moreover,  even  with  the  best  of 
them  the  actual  amount  of  formaldehyde  produced  has  been 
but  a  comparatively  small  proportion  of  the  amount  that  is 
theoretically  possible.  It  is  not  improbable  that  these  defects 
may  be  overcome  in  some  of  the  devices  subsequently  to  be 
introduced. 

The  methods  that  have  found  most  favor  are  those  in  which 
the  nascent  gas  is  liberated  from  its  watery  solution  and  from 
its  solid  polymerized  products.  In  the  former  case  this  is 
accomplished  through  the  employment  of  autoclaves  in  which 
the  solution,  either  formalin  or  formochloral  (a  mixture  of 
formalin,  practically  free  of  methyl  alcohol,  and  calcium  chlo- 
ride) is  placed,  and  is  brought  to  a  high  temperature  under 
pressure.  When  it  is  sufficiently  heated,  the  gas  is  liberated 
by  the  opening  of  a  valve  and  is  conveyed  through  a  tube 
into  the  apartment  to  be  disinfected ;  or  in  other  forms  of 
apparatus  a  temperature  sufficiently  high  to  dissociate  the  gas 
is  obtained  by  passing  its  watery  solution  through  a  highly- 
heated  metal  coil,  which  in  turn  is  connected  with  a  tube  for 
the  delivery  of  the  gas  into  the  apartment  for  disinfection. 

By  the  latter  process — /.  c,  the  decomposition  of  its  soHd 
form — tablets  of  compressed,  polymerized  formaldehyde  are 
simply  heated  in  a  properly  constructed  vessel  over  a  free 
flame.    By  the  high  temperature  to  which  they  are  thus  sub- 


268  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

jected  the  polymerized  body  is  decomposed  into  its  constitu- 
ent molecules,  and  formaldehyde  is  set  free  as  such. 

Since  no  two  apartments  present  identically  the  same  con- 
ditions, it  is  manifestly  impossible  to  lay  down  fixed  laws 
for  the  use  of  formaldehyde  as  a  practical  disinfectant  for 
dwellings,  and  doubtless  it  is  this  circumstance  that  is  in 
part,  at  least,  answerable  for  the  discrepancy  in  the  results 
of  its  use  by  different  investigators.  It  may  be  said, 
however,  that  for  general  practice  the  following  proced- 
ures are  necessary  :  Because  of  the  diffusibility  of  the  gas 
at  ordinary  dwelling-room  temperature  all  cracks  and  crev- 
ices through  which  it  could  escape  from  the  room  are  to  be 
closed,  either  through  the  use  of  adhesive  paper  or  by  plug- 
ging with  rags  or  raw  cotton.  If  either  the  lamp,  generating 
the  gas  from  methyl  alcohol,  or  the  apparatus  that  liberates 
it  from  solid  tablets  of  polymerized  formaldehyde  are  to  be 
used,  they  are  placed  in  the  center  of  the  room  and  ignited  ; 
if  the  former,  at  least  i  quart  of  methyl  alcohol  is  to  be 
burned  for  every  lOOO  cu.  ft.  of  room  to  be  disinfected;  if 
the  latter,  from  50  to  75  tablets  are  to  be  decomposed  for  the 
same  cubic  air-space.  The  room  is  to  be  kept  closed  for  ten 
to  twelve  hours,  after  which  it  should  be  thoroughly  aired. 
By  either  of  these  procedures  it  is  necessary  to  leave  a  lighted 
lamp  unattended  in  a  closed  room  for  a  comparatively  long 
time,  so  that  it  is  advisable  to  take  precautions  against  fire ; 
such,  for  instance,  as  standing  the  apparatus  upon  a  large 
sheet  of  tin  or  in  a  large  tin  pan. 

If  either  of  the  forms  of  apparatus  used  to  generate  the  gas 
from  its  watery  solution  be  employed,  this  is  set  in  operation 
in  the  hallway  or  in  an  adjoining  room,  and  the  gas  is  passed 
from  the  generator  into  the  room  by  means  of  a  tube  passed 
through  the  key-hole,  the  room  in  this  case,  as  in  the  other, 
having  been  made  as  nearly  air-tight  as  possible.  In  this 
process  a  safe  rule  is  to  evaporate  the  gas  from  one  pound 
of  formalin  or  formochloral  for  every  1000  to  1200  cu.  ft.  of 
space  to  be  disinfected,  and  to  keep  the  room  closed  for  five 
or  six  hours  after  the  gas  has  been  generated.  At  the  end 
of  this  time  the  room  should  be  thoroughly  aired. 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    269 

In  our  personal  experience  we  have  obtained  the  most 
satisfactory  results  through  the  use  of  formalin  to  which  10 
per  cent,  of  glycerin  has  been  added,  as  recommended  by 
Schlossmann  ;  and  through  the  employment  of  a  generator ' 
after  the  plan  of  that  devised  by  Novy  and  Waite — viz.,  a 
simple  copper  retort  into  which  the  formalin-glycerin  mixture 
is  placed  and  from  which  the  gas  is  disengaged  by  heat  and 
conveyed  through  a  tube  into  the  room  to  be  disinfected 
(Fig.  42).  In  these  tests  we  found  that  80  per  cent,  of  all 
exposed  infected  objects  in  a  room  could  be  disinfected  when 
500  c.c.  of  the  formalin-glycerin  mixture  per  1000  cu.  ft.  of 
air-space  was  completely  evaporated  and  the  room  kept 
closed  for  three  or  four  hours. 

After  disinfection  the  disagreeable  and  irritating  odor  of 
formaldehyde  may  be  removed  by  sprinkling  the  room  with 
ammonia  water,  or  by  placing  in  the  room  several  open  pans 
containing  ammonia. 

The  gas  is  not  poisonous,  though  very  irritating.  It  has 
little  or  no  destructive  action  upon  objects  in  the  room  and, 
as  stated,  is  highly  to  be  recommended  as  a  superficial  disin- 
fectant, though  its  penetrating  action  is  uncertain. 

In  addition  to  its  disinfecting  properties  formaldehyde  is  a 
marked  deodorizer,  combining  to  form  odorless  compounds 
with  such  bodies  as  sulphuretted  hydrogen,  ammonia,  mer- 
captan,  and  other  offensive  products  of  decomposition.  For 
the  disinfection  and  deodorization  of  closets,  vaults,  safes,  etc., 
in  which  such  malodorous  and,  at  times,  infected  objects,  as 
bank-notes,  public  documents,  and  papers  are  stored,  it  has 
proved  to  be  of  very  great  service. 

Carbolic  acid  is  employed  as  a  disinfectant,  in  the  form  of 
watery  solutions  of  from  3  to  5  per  cent,  strength  by  weight. 

It  is  unreliable  for  the  disinfection  of  spores,  but  occupies 
a  high  place  in  the  list  of  disinfectants  to  be  used  against  the 
non-spore -forming  infective  bacteria.  In  5  per  cent,  solution 
it  is  a  useful  disinfectant  for  sputum,  vomited  matters,  and 
fecal  evacuations  ;   and  in  2  per  cent,  solution  may  be  safely 

^  The  apparatus  mentioned  is  made  by  Messrs.  Chas.  Lentz  &  Sons,  Phila.  ; 
a  similar  apparatus  is  also  made  by  Messrs.  Parke,  Davis,  &  Co. 


2/0  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

employed  as  a  wash  for  wooden  surfaces,  furniture,  floors, 
etc. 

In  its  crj^'stalline  form  and  in  its  stronger  solutions  it  is 
possessed  of  poisonous  properties,  and  sliould  always  be  so 
labelled,  to  avoid  accidents.  It  is  also  in  these  forms,  espe- 
cially the  crystalHne,  an  active  escharotic,  and  should  not 
therefore  be  handled  with  the  fingers. 

In  order  to  obtain  its  germicidal  action  its  solution  must 
be  thoroughly  mixed  with  the  matters  to  be  disinfected,  so 
that  it  comes  in  intimate  contact  with  them. 

It  is  valueless  as  an  air-disinfectant,  and  neither  spraying 
the  room  nor  the  placing  about  of  open  vessels  containing 
carbolic  acid  has  any  appreciable  effect  beyond  the  genera- 
tion of  its  odor  throughout  the  premises. 

A  I  per  cent,  solution  of  the  pure  acid,  when  allowed  to 
act  under  the  most  favorable  circumstances  (/.  e.,  in  labo- 
ratory experiments),  is  destructive  to  the  pathogenic  cocci, 
the  bacillus  of  typhoid  fever,  the  spirillum  of  Asiatic  cholera, 
and  numerous  other  non-spore -forming  pathogenic  bacteria. 
In  practice,  however,  stronger  solutions  should  be  employed, 
rarely  weaker  than  2  per  cent.,  for  the  reason  that  the  con- 
ditions under  which  it  is  to  act  are  always  much  less  favor- 
able than  are  those  under  which  the  laboratory  tests  are  made. 

A  convenient  method  for  using  carbolic-acid  solutions  is 
to  dissolve  about  six  ounces  of  the  pure  carbolic  acid  in  a 
gallon  of  hot  water,  which  is  approximately  a  5  per  cent, 
solution — that  is,  a  saturated  solution.  From  this  dilutions 
may  be  made,  and  it  is  advisable  not  to  use  dilutions  weaker 
than  from  2  to  2^  per  cent. 

Carbol-sidphuric  acid  represents  a  mixture  of  equal  parts 
of  crude  carbolic  acid  and  concentrated  sulphuric  acid.  The 
mixture  is  made  by  slowly  adding  to  the  carbolic  acid,  which 
is  contained  in  a  vessel  that  stands  in  water  for  the  purpose 
of  checking  the  development  of  heat,  an  equal  volume  of 
concentrated  sulphuric  acid. 

From  this  mixture  solutions  of  from  2  to  3  per  cent,  can 
be  made  in  water.  This  is  not  an  actual  solution,  but  is 
rather  an  emulsion. 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    2/ 1 

Sulphuric  acid  not  only  renders  the  insoluble  crude  car- 
bolic acid  more  soluble,  but  increases  its  germicidal  proper- 
ties as  well.  The  preparation  is  used  only  for  the  disinfec- 
tion of  sinks,  cesspools,  urinals,  gutters,  privy-vaults,  etc.  It 
should  not  be  allowed  to  remain  for  any  considerable  length 
of  time  in  contact  with  metal,  brass  fixtures,  etc.  Its  disin- 
fectant value  is  about  equal  to  that  of  the  pure  acid,  but  the 
cost  of  the  preparation  is  only  one-third  to  one-half  that  of 
the  pure  acid. 

Carbol-soap  solution  is  prepared  as  follows :  dissolve  3 
parts  of  soft  soap  in  100  parts  of  warm  water.  When  the 
solution  is  complete  add,  slowly  stirring  as  it  is  added,  5 
parts  of  the  commercial  (not  the  pure)  carbolic  acid.  This 
forms  a  permanent  solution  having  about  the  same  disin- 
fectant value  as  a  solution  of  the  pure  acid,  and  is  useful  for 
the  disinfection  of  bed-  and  body-clothing  before  they  are 
sent  to  the  laundry.  The  articles  should  be  thoroughly 
immersed  in  it  and  allowed  to  remain  for  two  or  three  hours. 
It  may  also  be  used  for  general  scrubbing  purposes.  Since 
it  has  some  bleaching  properties,  it  is  best  to  restrict  its  use 
to  the  disinfection  of  white  goods. 

The  cresols — meta-,  para-,  and  ortho-cresol — obtained  by 
distillation  from  coal-tar  and  from  crude  carbolic  acid,  have 
been  shown  to  possess  high  germicidal  properties.  Their 
activity  is  increased  by  the  addition  of  an  equal  bulk  of  sul- 
phuric acid.  A  4  per  cent,  solution  of  these  acid  mixtures 
was  found  by  Frankel  to  destroy  spores  of  bacillus  anthracis 
as  follows  :  Meta-cresol,  in  eight  hours ;  para-cresol,  in  ten 
hours ;  and  ortho-cresol,  in  twenty  hours.  For  coarse  dis- 
infection Frankel  recommends  a  5  per  cent,  solution  of  a  mix- 
ture of  equal  parts  of  the  raw  cresols  and  cone,  sulphuric 
acid.  This  is  destructive  to  spores  in  five  to  six  hours,  while 
a  3  per  cent,  solution  is  germicidal  for  non-spore-forming  bac- 
teria, in  a  few  minutes.  It  may  be  used  for  the  same  pur- 
poses as  carbolic  acid. 

Tricresol  is  a  refined  mixture  of  the  three  cresols  men- 
tioned above,  in  about  the  following  proportions  :  Meta- 
cresol,  40  per  cent. ;  para-cresol,  25  per  cent;  ortho-cresol, 


272  HYGIENE    OF  TRAKSMISSFBLE   DISEASES. 

33  per  cent.  It  is  soluble  in  water  in  from  2.2  to  2.5  per 
cent.  It  possesses  about  three  times  the  germicidal  value  of 
carbolic  acid,  and  is,  therefore,  particularly  useful  for  disin- 
fection in  connection  with  surgical  and  obstetrical  work, 
especially  since  its  activity  is  but  little  diminished  by  the 
presence  of  albuminous  matters. 

Like  carbolic  acid,  the  cresols  are  poisonous. 

Solutions  of  tricresol,  in  water,  of  from  0.5  to  i.oper  cent, 
strength,  are  germicidal  for  sporeless  bacteria  in  a  few  min- 
utes and  in  a  few  seconds  respectively. 

Creolin  is  a  coal-tar  product  possessing  relatively  high  dis- 
infectant properties.  It  is  a  thick  fluid  resembling,  in  a  way, 
crude  carbolic  acid.  It  is  nearly  insoluble  in  water,  so  that 
dilutions  of  it  are  really  emulsions,  and  require,  therefore,  to 
be  thoroughly  agitated  each  time  they  are  used.  The  ger- 
micidal activities  are  interfered  with  by  the  presence  of  albu- 
minous matters  in  the  mass  to  be  disinfected.  In  practice  it 
is  used  as  a  2  to  5  per  cent,  emulsion  in  water,  and  should  be 
thoroughly  mixed  with  the  matters  to  be  disinfected.  It  is 
especially  useful  for  the  disinfection  of  urinals,  drains,  gut- 
ters, kennels,  stables,  etc. 

Bichloride  of  Mercwy. — Notwithstanding  the  conspicuous 
germicidal  properties  of  this  salt,  there  are  objections  to  its 
use  in  general  practice.  It  is  an  active  poison  ;  it  has  a  cor- 
roding action  upon  all  metals  with  which  it  comes  in  contact ; 
its  germicidal  activities  are  very  much  diminished  by  the 
presence  of  albuminous  matters  in  the  mass  to  be  disinfected, 
and  its  solutions  are  unstable  unless  protected  from  light  and 
air. 

Since  it  is  an  active  poison  whose  solution  is  colorless,  it  is 
always  wise  to  add  to  the  solution  some  inert  coloring  mat- 
ter— fuchsin,  for  instance — that  may  serve  to  distinguish  it 
and  thus  aid  in  avoiding  accidents. 

It  is  employed  for  general  disinfecting  purposes  in  solutions 
of  from  I  :  lOOO  to  1  :  5000  strength.  In  these  proportions 
it  is  useful  for  the  scrubbing  of  woodwork,  floors,  pavements, 
gutters,  etc.,  and  for  wiping  down  walls  that  are  not  injured 
by  it.     It  is  also  of  service  as  a  preparatory  disinfectant  for 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    273 

infected  clothing  before  they  are  sent  to  the  laundry,  though 
the  stains  of  blood  and  feces  are  rendered  almost  indelible  by 
long  soaking  in  this  solution.  The  clothing  should  be  im- 
mersed in  the  solution  for  two  hours. 

If  sublimate  solutions  are  to  be  employed  for  the  disinfec- 
tion of  feces,  sputum,  and  other  matters  containing  albumin, 
certain  precautions  must  be  taken — viz.,  the  mass  must  be 
mixed  in  either  an  earthenware  or  wooden  vessel,  as  corro- 
sive sublimate  both  destroys  and  becomes  itself  destroyed 
when  in  contact  with  metal.  To  prevent  its  precipitation  by 
albumin,  and  hence  loss  of  germicidal  powers,  the  solution 
should  always  contain  a  certain  amount  of  sodium  chloride. 

A  useful  formula  for  this  purpose  is  to  add  to  a  i  :  2000 
corrosive-sublimate  solution  common  salt  in  the  proportion 
of  from  0.5  to  I  per  cent. — in  other  words,  to  a  gallon  of  the 
sublimate  solution  four  teaspoonfuls  of  salt.  The  solution 
must  be  made  in  a  glass  or  wooden  vessel. 

Silver  nitrate  is,  according  to  all  experiments,  as  active  a 
germicide  as  corrosive  sublimate,  and  has  the  advantage,  ac- 
cording to  Behring,  over  the  mercury  salt  of  being  much  more 
trustworthy  for  use  with  substances  containing  albumin. 

In  I  :  1200  solution  it  destroys  anthrax  spores  in  seventy 
hours,  while  the  organisms  of  cholera,  typhoid  fever,  glan- 
ders, and  diphtheria  are  killed  in  two  hours  by  solutions  of 
I  :  2500. 

Chloride  of  Lime. — There  are  few  more  useful  disinfectants 
than  a  good  preparation  of  chloride  of  lime,  and  by  good 
preparation  is  meant  one  in  which  the  proportion  of  available 
chlorine  does  not  fall  below  25  to  30  per  cent. 

A  solution  in  water  of  such  a  preparation  in  the  strength 
of  0.5  to  I  per  cent,  by  weight  has  been  shown  to  disinfect 
typhoid  and  cholera  stools  completely  in  ten  minutes,  while 
a  I  per  cent,  solution  destroys  bacilhis  antJiracis,  in  laboratory 
experiments,  in  two  hours.  In  order  for  it  to  manifest  its 
germicidal  properties  it  is  necessary  that  the  solution  should 
be  brought  in  intimate  contact  with  the  objects  to  be  disin- 
fected. The  common  practice  of  placing  about  open  dishes 
containing  small  amounts  of  chloride  of  lime  has  little  more 

18 


274  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

effect  than  to  create  a  disagreeable  odor.  The  preparation  is 
cheap,  is  not  poisonous,  and  is  efficient ;  but  it  must  be  re- 
membered that  it  easily  undergoes  decomposition,  and  should 
be  made  up  fresh  when  it  is  needed  for  use,  and  should  be 
made  from  freshly-prepared  salts.  Its  efficiency  depends  upon 
the  amount  of  chlorine  contained  in  it  in  the  form  of  hypo- 
chlorites. 

The  disagreeable  odor  of  chloride  may  be  eliminated  by 
hanging  about  cloths  soaked  in  strong  soda  solution  after  dis- 
infection is  complete. 

Labarraque's  solution,  the  official  liqiior  sodce  clilorinatcgy 
depends  for  its  disinfecting  properties,  like  chloride  of  lime, 
upon  the  chlorine  present  as  hypochlorite.  It  should  contain 
at  least  3  per  cent,  of  available  chlorine. 

For  use  it  is  diluted  with  five  times  its  bulk  of  water, 
which  gives  a  solution  of  0.5  per  cent,  of  chlorine.  It  may 
be  used  for  the  same  purposes  as  the  chloride-of-lime  solution. 
It  is  a  more  attractive  preparation,  but  also  more  expensive, 
than  the  Hme  salt. 

Milk  of  Lime. — This  preparation  is  little  more  than  fluid 
"  whitewash."  It  is  made  by  slaking  i  quart  of  finely 
divided,  freshly  burned  lime  in  i  quart  of  water,  after  which 
3  quarts  of  water  are  added  and  the  mass  thoroughly  stirred. 

The  active  mixture  consists  of  lime  dissolved  and  sus- 
pended in  water.  It  should  always  be  freshly  prepared  and 
thoroughly  stirred,  before  being  applied  to  the  affected  mass. 

It  is  principally  used  for  the  disinfection  of  feces,  privies, 
gutters,  etc.,  and  when  so  employed  should  be  mixed  with 
the  mass  to  be  disinfected  until  the  whole  reacts,  distinctly 
alkaline,  as  determined  by  the  use  of  litmus  paper.  For  the 
disinfection  of  cholera  and  typhoid  stools  a  good  rule  is  to 
mix  thoroughly  with  them  an  equal  volume  of  milk  of  lime 
and  allow  it  to  stand  covered  for  one  hour,  after  which  it  may 
be  diluted  with  hot  water  and  poured  slowly  into  the  water- 
closet,  the  flush  of  the  closet  being  allowed  to  run  at  the  same 
time.  It  should  not  be  thrown  into  the  water-closet  without 
dilution,  for  the  reason  that  the  thick  mass,  especially  the  lime, 
may  accumulate  and  obstruct  the  pipes. 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    2"/$ 

Used  as  "  whitewash,"  it  is  an  important  disinfectant  for 
the  walls  of  hospitals,  barracks,  cellars,  and  other  apartments 
where  contagious  disease  or  infective  or  putrefactive  matters 
may  have  been. 

Soda  Solutions. — Experiment  has  shown  that  a  solution  of 
common  washing  soda,  especially  when  heated,  possesses  very 
marked  germicidal  activities.  In  addition  to  this  it  is  one  of 
the  most  useful  cleansing  agents.  For  scrubbing  and  general 
cleaning  purposes  the  solution  recommended  is  i  part  of 
soda  in  25  parts  of  boiling  water — i.  e.,  4  per  cent,  by  weight. 
Applied  hot,  this  not  only  removes  dirt,  but  disinfects  as  well. 

For  use  as  a  disinfectant  for  bed-  and  body-clothes,  instru- 
ments, eating-utensils,  etc.,  it  is  employed  in  a  2  per  cent, 
solution  at  boiling  temperature.  An  ordinary  wash-boiler  is 
a  convenient  apparatus  in  which  to  carry  out  the  process. 

Caustic  Soda:  Caustic  Potassa. — Solutions  of  either  of 
these  salts  in  the  strength  of  0.5  to  i  per  cent,  are  destruc- 
tive in  two  hours  to  such  pathogenic  bacteria  as  bac.  dipli- 
therics,  bac.  typhi  abdominalis,  and  the  glanders  bacillus. 
Spore-bearing  materials  require  stronger  solutions,  the  spores 
of  anthrax  being  killed  by  a  4  per  cent,  solution  in  forty-five 
minutes. 

Caustic  ammonia  has  no  effect  upon  spores,  but  is  germicidal 
in  two  hours  for  practically  all  non-spore-bearing  pathogenic 
bacteria  in  solutions  of  from  0.3  to  0.6  per  cent,  of  the  official 
solution  in  water. 

Acids. — Many  infective  micro-organisms  are  extremely  sen- 
sitive to  unusual  variations  in  the  reaction  of  the  medium  in 
which  they  are  located.  The  majority  of  acids,  especially  the 
mineral  acids,  serve,  therefore,  a  useful  purpose  when  used  as 
disinfectants,  though  their  employment  is  limited  because  of 
their  effect  upon  metal  objects,  with  which  they  may  come 
in  contact. 

Hydrochloric  acid  in  the  strength  of  5 :  1000  solution 
readily  destroys  non-spore-forming  pathogenic  bacteria  in 
two  hours,  though  in  even  four  times  this  strength — /.  e., 
2  per  cent. — it  requires  as  long  as  ten  days  to  kill  the  spores 
of  anthrax. 


2/6  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

SidpJmric  acid,  in  from  2  to  15  per  cent,  solution,  re- 
quires from  fifty-three  hours  to  eight  days  to  destroy  spores  ; 
while  in  5  :  lOOO  it  is  fatal  to  practically  all  non-spore -forming 
bacteria  having  pathogenic  properties,  in  two  hours. 

Pcnna)iga]iatc  of  potash  has  little  or  no  disinfecting  powers 
when  used  in  its  ordinary  watery  solution.  It  is  employed  in 
this  condition  more  as  a  deodorizer.  The  strength  of  the 
solution  is  about  4  ounces  of  the  salt  to  the  gallon  of  water. 
When  used  in  its  strong  alkaline  or  acid  solution  a  low  degree 
of  disinfective  activity  may  be  exhibited,  but  it  is  never  to  be 
relied  upon. 

Stdpliate  of  iron  is  used  as  a  disinfectant  and  deodorizer  for 
privy-vaults,  cesspools,  fecal  matters,  etc. 

For  this  purpose  4  pounds  of  the  salt  dissolved  in  a  gallon 
and  a  half  of  water  are  to  be  used  for  every  cubic  yard  of  the 
vault  to  be  treated. 

As  a  germicide  it  is  not  so  trustworthy  as  are  the  other 
preparations  recommended  for  this  purpose,  and  though  fre- 
quently used  its  benefits  are  more  as  an  antiseptic  and  deodor- 
izer than  as  an  actual  germicide. 

Garden  Earth. — Well-dried  and  sifted  garden  loam  has 
marked  deodorizing  powers  over  fecal  matters. 

If  mixed  with  a  very  small  quantity  of  pulverized  lime,  so 
that  the  latter  is  present  in  from  4  to  6  per  cent,  by  weight, 
it  is  said  to  have  a  certain  degree  of  disinfective  action,  and 
this  mixture  is  recommended  by  some  authors,  but  unfortu- 
nately the  lime,  by  its  germicidal  action  upon  the  bacteria  in 
the  earth,  may  defeat  the  very  object  for  which  the  earth  is 
used — /.  f.,  the  destruction,  by  nitrificatioji,  of  the  organic 
constituents  of  the  feces,  and  by  this  the  prevention  of  putre- 
factive odors. 

Garden  loam  cannot  be  regarded  as  a  trustworthy  disin- 
fectant, and  if  the  evacuations  require  disinfection,  some  other 
safer  process  should  be  employed.  It  is  only  a  deodorizer 
and  disintegrator. 

For  deodorization  enough  dried  earth  must  be  used  to 
cover  the  feces  completely.      Moisture  interferes  with  the 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    2// 

process  of  deodorization  in  direct  proportion  to  the  amount 
present. 

Chalk,  gravel,  or  sand  is  not  suitable  for  this  purpose. 

The  figures  given  above  for  the  strengths  of  solutions  of 
the  various  disinfectants  recommended  are  those  obtained  by 
laboratory  tests  under  the  most  favorable  conditions. 

They  teach  that  in  the  practical  use  of  disinfectants  it  does 
not  answer  to  sprinkle  about  the  premises  or  over  the  mass 
to  be  disinfected  a  little,  more  or  less,  of  the  disinfectant  to 
be  used,  but  that  a  definite  quantity  must  be  employed  for  a 
minimum  length  of  time  before  the  best  results  can  be  ex- 
pected.  Thus,  for  instance,  it  has  been  said  above  that  a 
3  per  cent,  solution  of  carbolic  acid,  a  o.  i  per  cent,  solution 
of  corrosive  subUmate,  and  a  i  per  cent,  solution  of  chloride 
of  lime  are  useful  disinfectants,  but  this  does  not  mean  that 
the  addition  of  such  substances  at  random  to  the  infected 
matters  always  results  in  successful  disinfection.  It  means 
rather  that  the  agents  must  be  in  intimate  contact  with  the 
materials  to  be  disinfected,  in  proportions  not  less  than  those 
expressed  by  the  figures  given.  Thus,  if  it  were  desirable  to 
disinfect  a  mass  of  feces  of  about  a  liter  capacity  with  chlo- 
ride of  lime  in  the  strength  of  i  per  cent,  solution  it  would 
be  necessary  to  mix  thoroughly  with  it  either  lo  grams  of  the 
salt  in  substance,  or,  what  would  be  better,  a  liter  of  a  watery 
solution  of  the  salt  in  the  strength  of  2  per  cent.,  so  that  in 
the  resulting  mixture  chloride  of  lime  would  be  present  in 
not  less  than  half  this  amount — i.  e.,  the  desired  i  per  cent. 
So  it  is  with  the  other  disinfectants  mentioned. 

Special  Chemical  Disinfection. — Privy  Vaults,  Evac= 
uations,  etc. — In  the  first  place,  privy  vaults,  or  any  other 
contrivance  for  the  accumulation  of  excrementitious  matters, 
should  not  be  tolerated  in  thickly-populated  communities. 
Unfortunately,  however,  they  are  occasionally  encountered  and 
therefore  require  care.  By  the  frequent  removal  of  the  con- 
tents of  cesspools  and  the  continuous  employment  of  disin- 
fecting materials  we  not  only  prevent  the  offensive  odors  con- 
sequent  upon  putrefaction,  but   check  the  development   or 


2/8  HYGIENE    OF  TRANSMISSIBLE   DISEASES. 

destroy  outright  the  germs  of  disease  that  may  gain  access 
to  them.  It  is  often  recommended  to  use  deodorants  in  this 
connection,  under  ordinary  circumstances,  and  to  employ  dis- 
infectants only  when  the  privy  is  known  to  contain  infective 
matters,  such  as  cholera  or  typhoid  stools.  Since  it  is  just  as 
simple  and  as  cheap  and  always  safer  to  employ  disinfectants 
as  a  routine  practice,  we  prefer  to  recommend  this  procedure. 
By  their  frequent  use  the  development  of  all  germ  life  is 
checked,  and  therefore  putrefaction  with  its  bad  odors  is  also 
prevented. 

The  cheapest  and  probably  the  most  practical  disinfectant 
for  the  contents  of  privy  vaults  is  milk  of  lime,  made  after 
directions  given  above.  This  should  be  mixed  with  the  mass 
to  be  disinfected  in  the  proportion  of  about  2  per  cent,  of  the 
contents  of  the  vault,  or  it  should  be  added  and  be  thoroughly 
mixed  until  the  entire  mass  reacts  distinctly  alkaHne  to  litmus 
paper.  Another  rule  is  to  add  to  the  cesspool  about  2  liters 
(quarts)  of  milk  of  Hme  daily  for  each  individual  using  the 
privy.  By  beginning  with  an  empty  and  clean  privy  vault 
and  adding  the  lime  mixture  daily,  not  only  is  the  odor  pre- 
vented, but  the  mass  is  continuously  disinfected. 

Sulphate  of  iron  is  highly  recommended  for  the  suppres- 
sion of  offensive  odors  from  such  receptacles. 

The  liberal  sprinkling  of  chloride  of  lime  in  powder  over 
the  mass  in  a  cesspool,  not  only  serves  to  disinfect  but  to 
check  putrefactive  odors  as  well. 

It  is  always  advisable,  however,  where  cesspools  must  be 
used,  to  disinfect  thoroughly  all  infected  matters,  such  as  ty- 
phoid, dysenteric,  and  cholera  stools,  before  they  are  emptied 
into  the  vault,  as  disinfection  is  much  more  certainly  and 
easily  accomplished  with  such  small  volumes  of  matter  than 
it  would  be  after  the  entire  mass  in  the  vault  had  become 
infected. 

Water-closets,  Urinals,  and  Sinks. — The  continuous 
treatment  of  water-closets,  urinals,  and  sinks  is  called  for 
more  to  suppress  bad  odors  than  to  destroy  infective  matters. 
As  a  routine  practice  cleanliness,  in  this  respect,  is  above  all 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.   279 

other  modes  of  procedure,  and  in  private  houses  is  usually 
all  that  is  required. 

In  public  places,  however,  it  is  to  be  recommended  that 
the  ordinary  modes  of  mechanical  cleaning,  often  only  imper- 
fectly performed,  should  be  supplemented  by  steps  to  pre- 
vent putrefaction  and  consequent  bad  odors.  For  this  pur- 
pose the  3  per  cent,  carbolic-acid,  or  the  i  per  cent,  chloride- 
of-lime  solution  will  be  found  useful.  The  closet-pans  and 
the  urinals  should  be  thoroughly  brushed  once  a  day  with 
the  disinfectant. 

The  odor  that  is  almost  constant  in  and  about  public 
urinals  is,  as  a  rule,  due  to  neglect  of  the  ordinary  laws 
of  cleanliness.  It  arises  from  the  decomposition  of  urine 
that  has  not  been  passed  into  the  proper  receptacle.  It  may 
be  obviated  by  constant  scrubbing,  by  the  free  sprinkling  of 
the  premises  with  either  of  the  solutions  named,  or  may  be 
masked  by  placing  lumps  of  camphor  or  of  carbolized  soap 
in  the  urinals. 

Where  infective  matters  have  gained  access  to  water-closets 
or  sinks,  these  receptacles  should  be  thoroughly  scrubbed 
with  5  per  cent,  carbolic-acid,  or  2  per  cent,  chloride-of-lime 
solution.  Sufficient  of  the  solution  should  be  passed  into 
them  to  fill  the  trap  completely,  and  there  should  always  be 
a  residue  of  from  a  pint  to  a  quart  of  the  solution  in  the  body 
of  the  fixture.  This  should  be  repeated  after  each  time  the 
closet  is  used  for  infected  discharges.  As  stated  above,  how- 
ever, infected  evacuations  should  always  be  disinfected  before 
they  are  thrown  into  the  closets. 

Stables  and  Cellars. — When  suspected  of  being  infected 
the  walls,  floors,  ceilings,  and  all  objects  upon  which  sus- 
picion rests  should  be  thoroughly  saturated,  without  other- 
wise disturbing  them,  with  either  the  5  per  cent,  carbol-sul- 
phuric  acid  solution,  or  5  per  cent,  creolin  solution,  or  2  per 
cent,  chloride-of-lime  solution,  and  kept  wet  with  it  over 
night.  The  premises  should  then  be  thoroughly  cleaned 
with  a  boiling  4  per  cent,  solution  of  common  washing  soda. 

In  the  case  of  cellars  and  the  less  elaborate  stables,  the 
walls  and  ceilings  should  be  whitewashed. 


28o  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

The  harness  worn  by  diseased  animals,  especially  bits, 
should  be  first  disinfected  with  one  of  the  solutions  named 
above,  then  thoroughly  washed  with  hot  soda  solution,  and 
finally  rinsed  with  warm  water  and  dried. 

The  disinfection  should  always  precede  the  cleansing,  other- 
wise infective  matters  in  a  living  state  may  be  disseminated 
from  the  infected  focus  during  the  ordinary  steps  of  the 
cleansing  process. 

Disinfection  of  Wells  and  Cisterns. — It  is  not  necessary 
to  emphasize  the  fact  that  where  possible  all  suspicious  drink- 
ing waters  should  be  abandoned,  and  that  water  for  domestic 
uses  should  be  beyond  suspicion  of  pollution  ;  but  circum- 
stances may  arise  through  which  a  well,  the  only  readily 
available  source  of  supply  for  an  isolated  family,  settlement, 
or  company  of  soldiers,  may  become  temporarily  infected  and 
seriously  inconvenience  the  users  of  the  water,  unless  some 
safe  remedy  is  at  hand.  To  meet  the  requirements  of  such 
cases  efforts  have  been  made  to  determine  in  how  far  it  is 
possible  to  disinfect  wells,  with  the  result  of  demonstrating 
that  this  is  a  practicable  procedure,  providing  the  pollution 
has  been  but  to  a  slight  extent  and  is  not  continuous.  Of 
course,  a  well  fed  by  polluted  ground  water,  or  a  well  into 
which  infective  matters  are  continuously  and  unavoidably 
passing  from  the  surface,  cannot  be  rendered  safe  by  any 
process  of  disinfection,  and  should  be  abandoned. 

The  methods  that  are  recommended  for  the  disinfection  of 
wells  that  have  been  only  temporarily  polluted,  as  by  the 
accidental  deposition  into  them  of  infective  matters  from 
above,  or  by  the  washing  into  them  of  such  matters  as  a 
result  of  excessive  rains,  are  as  follows  : 

If  the  water  be  raised  to  the  surface  by  a  pump,  remove 
the  latter  and  pour  down  the  pipe  a  mixture  of  equal  parts  of 
raw  carbolic  acid  and  sulphuric  acid  until  it  is  present  in  the 
proportion  of  about  5  per  cent,  of  the  contents  of  the  well. 
The  water  should  be  thoroughly  stirred  so  as  to  complete 
the  mixing  of  the  acids  with  it,  and  the  walls  of  the  well 
should  be  scrubbed  with  brooms  dipped  in  the  water.  The 
inside  of  the  delivering  pipe  should  be  thoroughly  cleaned  by 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    28  I 

mechanically  scrubbing  it  with  a  long-handled  brush  wet  with 
the  acid  solution.  After  standing  for  twenty-four  hours  the 
contents  should  be  pumped  out,  the  slime  from  the  bottom 
thoroughly  removed,  the  well  allowed  to  refill ;  this  water  is 
again  pumped  out,  and  this  must  be  repeated  until  all  traces 
of  the  acid  have  disappeared.  Another  plan  consists  in  the 
use  of  lime.  Here  the  delivery  pipe,  if  a  pump  is  used,  is  to 
be  scrubbed  on  its  inside  with  strong  carbolic-acid  solution  ; 
there  is  then  to  be  thrown  into  the  well  about  40  to  50  pounds 
of  freshly  burned  lime ;  after  the  Hme  dissolves,  the  walls  of 
the  well  are  to  be  thoroughly  scrubbed  with  its  solution.  The 
contents  are  then  pumped  out,  or  otherwise  removed ;  the 
slime  from  the  bottom  is  baled  out  completely,  and  lime  in  the 
same  proportion  is  again  added  and  allowed  to  slake  and 
dissolve  as  the  well  refills.  The  whole  is,  after  twenty-four 
hours,  to  be  thoroughly  stirred  and  again  removed.  The 
well  is  again  allowed  to  refill  and  is  re-emptied,  and  this 
is  continued  until  the  pumped  water  is  practically  free  from 
lime. 

With  tube  wells  only  the  inside  of  the  tube  needs  atten- 
tion. This  should  be  thoroughly  brushed  with  the  carbol- 
sulphuric-acid  mixture,  and  water  pumped  through  it  until 
the  acid  (phenol)  reaction  disappears. 

Cisterns  should  be  treated  as  wells. 

These  procedures  are  not  ideal  from  a  sanitary  standpoint, 
but  circumstances  may  arise  when  they  would  be  far  better 
than  no  precautions  at  all. 

For  drinking  purposes  alone  all  water  that  is  of  necessity 
derived  from  suspicious  sources  should  be  boiled  before 
being  used,  and  no  process  of  chemical  disinfection  can  in 
any  way  compare  with  this  method  from  the  standpoint  of 
safety  and  practical  utility. 

Disinfection  of  the  Hands. — Of  the  numerous  methods 
recommended  only  two  will  be  given  as  thoroughly  trust- 
worthy— viz.,  that  of  Fiirbringer  and  that  of  Welch,  as 
developed  at  the  Johns  Hopkins   Hospital. 

Furbringer'' s  method  : 

I.  Remove  all  dirt  from  under  and  around  the  nails. 


282  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

2.  Brush  nails  and  skin  of  hands  thoroughly  with  soap 
and  hot  water. 

3.  Immerse  in  alcohol,  95  per  cent,  for  not  less  than  a 
minute,  and  before  this  evaporates. 

4.  Plunge  the  hands  in  i  :  500  corrosive-sublimate  or  3 
per  cent,  carbolic-acid  solution,  and  thoroughly  wash  them 
for  at  least  a  minute,  after  which  the  hands  may  be  rinsed  in 
warm  water  and  dried. 

WclcJCs  method  : 

1.  The  hands  and  nails  are  to  be  thoroughly  cleansed  with 
hot  water  and  soap.  The  water  is  to  be  as  hot  as  can  be 
borne,  and  the  brush  used  is  to  have  been  sterilized  by 
steam.  This  preliminary  brushing  to  occupy  from  three  to 
five  minutes. 

2.  The  hands  are  then  rinsed  in  clean  warm  water. 

3.  They  are  then  immersed  for  one  or  two  minutes  in  a 
warm,  saturated  solution  of  permanganate  of  potash.  While 
in  this  solution  they  are  rubbed  thoroughly  with  a  sterilized 
swab  of  absorbent  cotton. 

4.  They  are  then  placed  in  a  warm,  saturated  solution  of 
oxalic  acid  and  kept  there  until  completely  decolorized. 

5.  They  are  then  thoroughly  washed  in  clear  sterilized 
water  or  salt  solution. 

6.  Finally,  they  are  immersed  for  two  minutes  in  i  :  500 
corrosive-sublimate  solution,  rinsed  in  water,  and  dried. 


Disinfection  through  Physical  Processes. — Under 
this  head  are  embraced  methods  for  the  destruction  of  infec- 
tive agents  by  the  use  of  such  physical  influences  as  are 
antagonistic  to  their  vitality,  as  for  example,  heat,  cold,  elec- 
tricity, light,  and  pressure. 

Disinfection  by  Heat. — Heat  in  one  form  or  another  is 
the  most  trustworthy  germicide  that  we  possess.  It  is  em- 
ployed according  to  circumstances  as  ordinary  fire,  free 
flames,  and  as  dry  heat,  the  articles  to  be  disinfected  being 
protected  in  a  properly-constructed  oven;  as  boiling  water; 
as  streaming  or  live  .steam  ;  and  as  steam  under  pressure. 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    283 

Fire. — The  free  flames  are  resorted  to  only  when  it  is 
desirable  to  consume  valueless  articles  completely  which 
would  hardly  pay  for  the  trouble  of  disinfecting  by  the 
usual  processes,  such,  for  example,  as  old  straw  mattresses, 
worn-out  clothing,  useless  furniture  or  bed-clothing,  etc. 

Dry  Heat. — The  process  of  disinfection  by  dry  heat  in 
ovens  constructed  for  the  purpose  was  formerly  much  more 
in  vogue  than  it  is  at  present.  It  has  been  practically  aban- 
doned for  the  reasons  that  dry  heat  has  but  little  penetrating 
power  as  compared  with  steam  ;  that  it  requires  a  longer 
time  for  disinfection  than  is  necessary  for  steam  ;  and  that 
the  high  temperature  and  prolonged  exposure  are  together 
detrimental  to  many  articles  that  are  disinfected  by  this 
method. 

Complete  disinfection  by  dry  heat  cannot  always  be  antici- 
pated, even  when  a  temperature  of  130°  to  140°  C.  has  been 
maintained  for  as  long  as  three  hours,  conditions  that  are 
manifestly  destructive  to  many  articles  that  might  be  sub- 
jected to  the  process. 

It  is  only  to  be  recommended  when  no  other  means  are  at 
hand. 

Boiling. — Boiling  water  destroys  all  pathogenic  bacteria 
and  their  spores  in  five  minutes.  Its  disinfecting  action  is 
further  increased  by  the  addition  of  i  to  2  per  cent,  of  soda. 
This  is  an  especially  handy  method  for  domestic  disinfection 
of  clothing,  eating-utensils,  etc.  A  wash-boiler  is  simply 
filled  with  water  or  soda  solution,  which  is  brought  to  the 
boiling  point,  and  the  articles  are  immersed  in  it  and  boiled 
for  five  or  ten  minutes.  For  the  disinfection  of  surgical 
instruments  the  boiling  soda  solution  has  found  very  general 
favor. 

Streaming  or  Live  Steam. — For  disinfection  by  this  method 
special  forms  of  apparatus  are  manufactured.  They  are  sold 
under  the  name  of  "  steam  sterilizers "  and  "  steam  disin- 
fectors."  The  simplest  construction  for  domestic  purposes 
is  the  ordinary  potato  steamer  that  is  used  in  the  kitchen, 
the  articles  to  be  disinfected  being  placed  in  the  upper  com- 
partment, the  water  in  the  lower,  the  cover  placed  in  position 


284  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

and  the  apparatus  placed  over  the  fire  and  the  water  kept 
boiling  from  ten  to  fifteen  minutes.  Several  refinements  of 
this  apparatus  are  now  to  be  had,  the  one  that  has  found 
most  favor  being  that  sold  as  "  Arnold's  Steam  Sterilizer." 
For  more  extensive  use  more  elaborate  and  varying  designs 
of  these  steamers  are  employed.  They  are  usually  of  such 
size  and  strength  as  to  accommodate  a  mattress,  or  a  bundle 


Fig.  43. — Portable   steam   disinfector,  equipped  with  chamber  of  sufficient 
size  to  accommodate  bed-clothing,  mattresses,  etc.,  and  a  boiler  for  generating 

steam. 

of  clothing,  etc.  (in  Fig.  43  is  depicted  a  very  serviceable 
portable  form  of  steam  disinfector).  The  principle  involved 
is  the  same  in  all  of  them,  the  point  aimed  at  being  to  keep 
the  articles  fully  exposed  to  the  penetrating  action  of  live 
steam  for  the  time  necessary  to  disinfect  them. 

For  complete  disinfection  with  streaming  steam  twenty-five 
minutes  is  necessary  with  loosely  placed  articles,  while  an 
hour  is  not  too  long  when  the  articles  are  closely  packed  in 
the  apparatus.  In  both  instances  the  time  of  disinfection  is 
to  be  reckoned  from  the  time  at  which  steam  begins  to  stream 
freely  from  the  apparatus. 

Steam  Jtiidcr  Pressure. — Disinfection  by  this  process  is  ac- 
complished by  subjecting  tlie  infected  articles  to  steam  that  is 
confined    in    a   closed   chamber.     As   it  is    under  additional 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    285 

pressure  because  of  its  confinement,  it  is  at  a  correspondingly 
higher  temperature.  By  this  method  the  disinfection  of  lar- 
ger, bulkier  objects,  such  as  bales  of  rags,  packages  of  mer- 
chandise, bundles  of  clothing,  etc.,  is  more  certainly  and 
quickly  accomplished,  because  of  the  higher  temperature  and 
excess  of  pressure  under  which  the  steam  is  kept.  For  dis- 
infection, on  the  large  scale,  as  at  hospitals,  lazarettos,  quar- 
antine stations,  etc.,  this  form  of  apparatus  has  almost  taken 
the  place  of  that  in  which  streaming  or  live  steam  is  used 


Fig.  44. — The  "  Kny-Sprague  "   disinfecting  chamber,   equipped  with  cars  for 
loading  the  chamber  with  articles  to  be  disinfected. 

(Fig.  44).  In  the  simplest  form  of  this  apparatus  the  articles 
are  placed  in  the  chamber,  the  door  closed  and  clamped,  and 
the  steam  turned  on  until  the  required  temperature  and  press- 
ure are  reached ;  this  is  then  maintained  for  the  time  neces- 
sary to  disinfection.  To  meet  important  requirements  certain 
modifications  have  been  made  in  the  construction  of  these 
chambers,  the  most  important  being  those  that  aim  to  dis- 
place all  air  from  the  chamber  and  from  the  meshes  and  pores 
of  the  articles  to  be  disinfected,  by  beginning  the  process  with 
the  exhaustion  of  the  air  from  the  chamber,  then  turning  in 
the  steam,  again  exhausting-  and  again  turning  in  the  steam, 
and  continuing  this  until  all  the  air  has  been  removed  and 
only  steam  is  in  contact  with  the  object.     This  is  manifestly 


286  HYGIENE    OF  TRANSMISSIBLE  DISEASES 

advantageous,  otherwise  portions  of  the  chamber  would  con- 
tain heated  air  and,  as  we  saw  above  (see  Dry  Heat),  hot  air 
has  not  the  germicidal  powers  of  steam.  Another  modifica- 
tion aims  to  assist  in  the  drying  of  the  objects  after  disinfec- 
tion, but  this  does  not  seem  to  be  necessary,  as  they  dry  very 
quickly  if  freely  opened. 

The  pressure  commonly  employed  in  this  form  of  disin- 
fection varies  between  -^  and  i  atmosphere,  and  often  more, 
and  for  ordinary  articles  thirty  minutes  under  from  ^  to  i 
atmosphere  suffice  for  disinfection  in  a  properly  constructed 
apparatus.  For  very  dense  objects,  such  as  closely  pressed 
bales  of  rags,  dry  goods,  etc.,  an  hour  to  an  hour  and  a  quar- 
ter is  necessary  ;  but  by  using  higher  pressure  this  time  may 
be  shortened.  This  form  of  disinfector  is  a  massive,  perma- 
nent fixture,  usually  constructed  of  iron  and  encased  in  a 
non-conducting  medium.  The  steam-supply  is  obtained  from 
a  boiler  either  especially  connected  with  the  disinfector  or 
from  one  close  by  that  is  used  for  other  purposes  and  which 
may,  as  occasion  requires,  be  called  upon  for  the  necessary 
amount  of  steam  for  disinfection  (Fig.  44). 

A  point  of  great  importance  in  connection  with  the  man- 
agement of  disinfecting  apparatus,  especially  the  large  cham- 
bers, is  the  precaution  that  should  be  taken  to  prevent  the 
reinfection  of  the  disinfected  articles  by  those  who  manipulate 
the  disinfector. 

With  disinfection  on  the  small  scale — /.  c,  domestic  dis- 
infection— the  person  who  has  handled  the  infected  objects 
should  thoroughly  disinfect  his  hands  and  arms  and  don  a 
sterilized  apron  while  the  apparatus  is  in  operation,  so  that 
in  removing  the  articles  after  the  process  is  complete  there 
will  be  no  danger  of  his  reinfecting  them. 

In  the  case  of  the  large  disinfecting  plants  it  is  customaiy 
to  have  them  erected  in  a  building  especially  designed  for 
their  accommodation.  This  should  be  constructed  with  a 
central  partition  at  right  angles  to  the  long  axis  of  the  room. 
The  disinfector  should  be  built  in  this  partition  so  that  its 
ends  project  into  the  apartments  on  either  side  of  the  parti- 
tion.    Running  along  the  long  axis   of  the   building   and 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    287 

through  the  disinfectors  are  tracks  on  which  run  light  cars  or 
trucks,  on  which  the  articles  to  be  treated  are  hung  or  packed. 
The  car,  constructed  of  iron  netting,  is  of  such  size  that  it  fits 
easily  into  the  disinfecting  chamber.  There  are  two  crews  of 
attendants  :  the  one  to  handle  only  the  infected  articles — /.  e., 
to  load  them  upon  the  carriage,  pass  them  into  the  chamber 
and  clamp  the  door ;  the  other,  to  handle  oitly  the  disinfected 
articles — i.  e.,  to  remove  them  from  the  apparatus  after  disin- 
fection, and  properly  distribute  them. 

While  on  duty  these  crews  do  not  come  in  contact  with 
one  another.  It  is  customary  also  to  distinguish  the  two  sets 
of  operators  by  uniforms  of  different  colors,  and  under  no 
circumstances  are  the  men  or  objects  from  the  infected  side 
of  the  building  allowed  to  mingle  with  those  on  the  disin- 
fected side.  The  only  channel  of  communication  is  the 
steam-chamber  in  the  wall ;  and  it  is  advisable  to  have  the 
doors  of  the  apparatus  so  arranged  that  both  are  not  open 
at  the  same  time  and  can  only  be  simultaneously  opened  by 
special  means.  By  simple  mechanical  contrivances  it  is  easily 
possible  to  accomplish  this  and  thus  shut  off  the  only  means 
of  direct  communication  between  the  infected  and  disinfected 
sides  of  the  apparatus.  The  goods  to  be  disinfected  should 
be  brought  to  the  station,  and  those  that  have  been  disin- 
fected are  taken  from  the  station  in  closed  wagons  that  are 
distinguished  from  each  other  by  colors  corresponding  to  the 
uniforms  of  the  crews  of  operators. 

The  uniforms  of  the  attendants  should  be  disinfected  at  the 
end  of  each  day,  and  the  walls,  floors,  etc.,  of  the  room  for 
reception  of  infected  articles  should  be  cleansed  each 
day  with  a  disinfecting  solution.  The  room  for  reception 
of  disinfected  articles  should  be  provided  with  closets,  etc., 
and  all  should  be  kept  scrupulously  clean.  For  their  own 
protection,  as  well  as  that  of  those  about  them,  the  opera- 
tors who  manipulate  the  infected  articles  should  be  provided 
with  conveniences  for  bathing  and  personal  disinfection. 

In  addition  to  heat  the  physical  influences  that  are  detri- 
mental and  destructive  to  the  vitality  of  infective  bacteria  are 
desiccation,  sunlight,  electricity,  and  vigorous  agitation ;  though 


288  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

these  are  not,  as  a  rule,  deliberately  used  for  the  disinfection 
of  dangerous  materials. 

Desiccation. — All  living  micro-organisms  are  sooner  or 
later  attenuated  in  their  pathogenic  activities,  and  finally 
killed,  by  drying.  With  the  non-spore-forming  species,  and 
particularly  certain  of  those  possessed  of  disease-producing 
powers,  this  effect  is  occasionally  conspicuously  manifest. 
With  the  spores  of  spore -forming  bacteria,  on  the  contrary, 
drying  requires  a  much  longer  time  to  attenuate  and  still 
longer  to  kill  them,  the  spores  of  certain  forms  retaining 
their  vitality  in  some  cases  for  many  years  when  dried 
(anthrax).  Fortunately,  however,  only  a  small  proportion 
of  the  known  disease-producing  bacteria  form  spores,  so  that 
desiccation,  even  such  as  occurs  with  the  ordinary  environ- 
ment of  pathogenic  bacteria  when  outside  the  body,  is  of 
importance  in  arresting  their  development,  and  ultimately  in 
destroying  their  vitality.  Thus,  for  instance,  in  laboratory 
experiments  it  has  been  demonstrated  that  the  spirillum  of 
Asiatic  cholera  when  dried  dies  in  from  three  hours  to  two 
days,  according  to  the  degree  of  desiccation ;  the  bacilli  of 
typhoid  lever,  of  tuberculosis,  and  of  diphtheria  resist  drying 
for  a  longer  time,  but  gradually  lose  their  vitality,  and  after 
from  a  few  weeks  to  months  die. 

The  influence  of  drying  in  checking  the  multiplication  of 
bacteria — for  none  of  them  develop  in  the  dry  state — and  of 
gradually  destroying  them,  is  of  manifest  importance  in  the 
spontaneous  elimination  of  infective  diseases. 

Sunlight. — A  large  proportion  of  the  sporeless  pathogenic 
bacteria  are  killed  by  the  direct  rays  of  the  sun.  In  labora- 
tory experiments  this  effect  is  very  striking,  many  species  being 
destroyed  in  the  presence  of  sunlight  and  air  in  so  short  a 
time  as  from  one  to  two  hours.  Diffuse  daylight  is  also  detri- 
mental to  pathogenic  micro-organisms,  though  its  action  is  less 
energetic  than  is  that  of  direct  sunlight.  These  experiments 
have  shown  that  the  bacillus  of  typhoid  fever  is  destroyed  in 
from  one  and  a  half  to  two  hours  by  direct  sunlight,  and  in 
five  hours  (l)uchncr)  by  diffuse  daylight.  Bacilhts  dipJitJicricB 
is  destroyed  by  from  one-half  to  one  hour's  exposure  to  the 


CHEMICAL  AND  PHYSICAL  PROPHYLACTIC  MEASURES.    289 

direct  rays  of  the  sun ;  and  Koch  states  that  the  tubercle 
bacillus  is  killed  by  sunlight  in  from  a  few  minutes  to  several 
hours,  according  to  the  thickness  of  the  mass  exposed,  and 
by  diffuse  daylight  in  from  five  to  seven  days.  Similarly, 
many  other  pathogenic  and  non-pathogenic  species,  such  as 
the  pneumococcus,  the  pyogenic  cocci,  the  anthrax  bacillus, 
the  cholera  spirillum,  and  others  are  seen  to  succumb  to  this 
influence. 

In  the  light  of  these  laboratory  demonstrations  Esmarch 
has  endeavored  to  determine  in  how  far  the  direct  rays  of  the 
sun  may  be  employed  for  practical  disinfection.  For  the  tests 
he  purposely  infected  such  articles  as  furniture-covers,  pil- 
lows and  pillow-cases,  furs,  etc.,  and  exposed  them  to  the 
direct  rays  of  the  sun  for  varying  lengths  of  time  and  under 
various  conditions.  As  the  result  of  these  experiments  he 
does  not  regard  direct  sunlight  as  worthy  of  confidence  for 
the  complete  disinfection  of  such  articles  as  he  employed  in 
the  test.  Its  disinfecting  activity  was  observed  oi^ly  upon 
surfaces  that  were  freely  exposed  to  it,  and  even  here  there 
were  irregularities  in  the  results.  The  time  required  for  its 
best  results  was,  moreover,  so  long  as  to  make  the  method 
impracticable  for  routine  purposes. 

Nevertheless,  there  is  every  reason  to  believe  that  the  con- 
tinuous daily  action  of  the  sun's  rays,  together  with  desicca- 
tion, is  an  important  factor  in  arresting  the  growth  and 
activities  of  pathogenic  bacteria  when  they  are  expelled 
from  the  animal  body. 

By  laboratory  experiments  it  has  been  shown  that  the  germi- 
cidal properties  of  the  sun's  rays  were  most  conspicuously 
present  at  the  blue  end  of  the  spectrum,  while  the  red  end 
had  little  or  no  detrimental  influence  upon  bacterial  life. 

Electricity. — The  germicidal  value  of  the  electrical  cur- 
rent is  made  evident  in  several  ways — viz.,  through  elec- 
trolytic decomposition  of  certain  chemical  compounds  with 
which  the  bacteria  may  be  associated,  by  which  detrimental 
substances  are  set  free ;  by  the  local  elevation  of  temperature 
at  the  positive  pole  ;  and  by  the  direct  action  of  the  electric 
current  upon  the  bacteria  themselves. 

19 


290  HYGIENE    OF   TRANSMISSIBLE   DISEASES. 

The  results  depend  upon  the  strength  of  current  and  time 
of  its  application.  It  has  been  successfully  employed  in  the 
purification  of  sewage  and  of  polluted  waters. 

Mechanical  Agitation. — The  results  obtained  by  a  number 
of  investigators  have  demonstrated  that  the  life-processes  of 
of  several  species  of  bacteria  are  markedly  interfered  with  by 
excessive  and  long-continued  shaking. 

In  some  instances  the  bacteria  exposed  to  continuous 
vibration  were  killed.  The  ordinary  motion,  such  as  bac- 
teria experience  in  a  current  of  quietly-flowing  water,  has 
apparently  no  such  effect.  Melzer  demonstrated  that  bac. 
mcgatJicriiim  when  exposed  for  four  days  to  continuous 
vibration  was  killed,  and  microscopic  examination  showed 
them  to  be  actually  disintegrated.  Hanson  has  found  that 
for  a  particular  water-bacillus  slight  motion  was  favorable, 
whereas  excessive  shaking-  was  fatal. 


PRECAUTIONS   IN  COMMUNICABLE   DISEASES.        29 1 


ADDITIONAL  PRECAUTIONS  OF  IMPORTANCE 
IN  THE  MANAGEMENT  OF  COMMUNICABLE 
DISEASES. 

ISOLATION,  THE    SICK-ROOM,  CLOTHING,  EXCRETA,  UTENSILS, 
ATTENDANTS,  ETC. 

Isolation. — In  the  modern  sense  the  term  "  isolation,"  as 
applied  to  contagious  diseases,  comprehends  not  only  the 
separation  of  the  infected  individual  from  those  that  are  not 
infected,  by  placing  him  in  a  separate  room  or  building,  but 
the  complete  obstruction  of  all  the  manifold  channels  through 
which  he  may  come  in  indirect  communication  with  those 
who  surround  him.  It  would  be  manifestly  absurd  to  place 
a  patient  in  an  "  isolation  ward  "  of  a  hospital  or  in  a  special 
room  of  a  private  dwelling  and  keep  him  there,  unless 
care  were  taken  that  all  articles  with  which  he  comes  in 
immediate  contact,  and  which  may  carry  the  infection,  were 
also  prevented  from  being  generally  used  throughout  the 
building. 

Formerly,  when  the  air  was  regarded  as  the  principal  dis- 
seminator of  infective  matters,  elaborate  preparations  were 
made  to  cut  off  all  aerial  communication  between  the  in- 
fected and  the  well,  and  isolation  pavilions,  wards,  etc.,  were 
so  constructed  as  never  to  communicate  directly  with  other 
buildings  in  which  non-contagious  diseases  were  located ; 
this  was  often  the  only,  or  at  least  the  most  conspicuous, 
step  that  was  taken  toward  the  isolation  of  the  patient. 
While  it  is  always  proper  to  confine  infectious  and  con- 
tagious patients  in  separate  rooms  in  private  houses  and  in 
special  wards  or  pavilions  in  hospital  cases,  for  the  reason 
that  their  management  is  thereby  very  much  simplified,  it  is 
important  that  we  should  fully  understand  this  to  be  only  a 
relatively  small  part  of  the  elaborate  precautions  now  recog- 
nized as  constituting  a  complete  and  trustworthy  system  of 
isolation.  Modern  investigation  has  shown  us  that  the  foun- 
dation-work of  a  successful  system  of  isolation  comprises  : 
(i)  Knowledge   of  the  mode  and   channels   through   which 


292  HYGIENE    OF   TRANSMISSIBLE  DISEASES. 

infective  matters  are  expelled  from  the  body  during  the 
course  of  special  groups  of  infectious  and  contagious  dis- 
eases ;  (2)  the  careful  employment  of  that  knowledge  in  the 
application  of  approved  means  to  the  destruction  of  such 
matters  as  soon  as  they  are  expelled. 

Thus,  for  instance,  during  the  desquamative  stage  of  the 
acute  exanthemata — the  period  at  which  the  danger  from 
contagion  is  believed  to  be  greatest — it  is  always  advisable  to 
prevent  the  dissemination  of  the  morbific  agents  from  the  skin 
in  the  form  of  epidermal  dust,  by  anointing  the  entire  body 
with  harmless  antiseptic  or  disinfecting  ointments.  These 
cause  the  epidermal  scales,  presumably  the  carriers  of  the 
infection,  to  adhere  to  the  patient,  to  whom  they  can  do  no 
harm,  and  from  whom  they  may  be  washed  with  disinfecting 
solutions ;  but  it  would  be  manifestly  absurd  to  subject  to 
this  treatment  a  cholera  or  typhoid  patient,  from  whom  the 
infective  particles  escape  only  from  the  bowels,  kidneys,  or 
with  vomited  matters. 

Isolation  means  ino7'e  than  simply  confining  the  patient  to  a 
separate  room  or  building.  It  comprises  in  addition  to  this 
the  employment  of  a  separate  attendant  who  comes  in  con- 
tact with  only  the  patient  or  patients  for  whom  he  or  she  is 
employed  to  care ;  the  disinfection  of  all  infective  matters  as 
soon  as  they  are  passed  from  the  patient  and  before  they  leave 
the  .sick-room  ;  the  disinfection  of  all  bed-  and  body-clothing 
as  soon  as  they  are  removed  from  the  patient  and  before  they 
leave  his  apartment ;  the  provision  of  separate  eating-utensils, 
handkerchiefs,  towels,  napkins,  clinical  thermometers,  tongue- 
depressor,  and  other  instrumental  accessories  ;  the  frequent 
cleansing  with  disinfecting  solutions  of  the  sick-room  and  its 
furniture  ;  the  frequent  general  bathing  of  the  nurse ;  and 
especially  the  careful  disinfection  of  the  hands  after  each 
manipulation  of  the  patient.  These  steps  will  now  be  treated 
of  in  more  or  less  detail. 

The  Sick-room. — The  room  should  be  light,  of  a  com- 
fortable temperature,  and  easily  aired.  Draughts  should  be 
avoided. 

The  furniture  should  be  of  the  simplest  kind,  and  neither 


PRECAUTIONS  IN  COMMUNICABLE  DISEASES.       293 

carpet  nor  hangings  should  be  permitted  unless,  in  the  case 
of  the  latter,  they  be  of  cotton  material  that  may  readily  be 
disinfected. 

The  room  should  be  provided  with  a  small  gas  stove  and 
a  wash-boiler  of  about  4  gallons  capacity,  or  with  a  steam 
sterilizer,  and  all  small  infected  articles,  such  as  napkins, 
towels,  handkerchiefs,  etc.,  should  be  immersed  in  boiling 
water  or  soda  solution,  or  steamed,  when  they  become  soiled 
and  before  being  laundered. 

The  patient  should  be  provided  with  his  own  eating-uten- 
sils, which  are  to  be  boiled  in  soda  solution  after  he  has  used 
them.  The  refuse  of  his  meals  should  be  thrown  into  a  cov- 
ered receptacle  containing  milk  of  lime,  or  i  per  cent,  chlo- 
ride-of-lime  solution,  which  should  be  renewed  each  day. 

The  furniture,  the  floor,  and  all  horizontal  surfaces,  such  as 
sills,  mantlepieces,  etc.,  should  be  frequently — at  least  once 
in  two  days — wiped  with  cloths  moistened  with  a  3  per  cent, 
solution  of  carbolic  acid  or  a  i  per  cent,  chloride-of-lime 
solution. 

The  knobs  of  the  doors  should  be  similarly  cleansed  every 
day. 

These  patients  should  be  provided  with  separate  clinical 
thermometer,  tongue-depressor,  and  whatever  other  instru- 
ments may  be  frequently  required  in  their  treatment.  When 
not  in  use  these  articles  should  be  kept  in  some  one  or  an- 
other of  the  disinfectant  solutions  after  having  been  cleansed 
in  such  solutions.  They  should  be  rinsed  off  in  warm  water 
before  being  used  again. 

When  soiled  by  evacuations,  secretions,  or  excretions,  the 
body-  and  bed-clothing  of  the  patient  should  be  removed  with 
as  little  agitation  and  commotion  as  possible,  and  at  once  im- 
mersed in  a  solution  of  • 

Carbolic  acid,  3  parts  ;. 

Common  soft  soap,  2      " 

Cold  water,  ■  100      " 

contained  in  a  covered  vessel  that  is  brought  to  the  bedside. 
This  prevents  the  dissemination  of  the  morbific  agents  that 


294  HYGIENE    OF  TRANSMISSIBLE   DISEASES. 

might  occur  if  the  infected  clothing  were  carried  loosely- 
through  the  house  or  through  the  wards  of  the  hospital.  As 
soon  as  the  objects  are  thoroughly  saturated  with  the  solu- 
tion, the  cover  is  replaced,  and  they  are  allowed  to  soak  for 
two  hours,  when  they  may  be  rinsed  out  in  clean  water  and 
subjected  to  the  ordinary  processes  of  the  laundry,  begin- 
ning preferably  with  boiling. 

The  reason  for  the  immersion  in  the  cold  carbolic-soap 
solution  is  that  this  not  only  destroys  all  non-spore-bearing 
bacteria,  but  in  the  cold  state  dissolves  out  all  blood  and  fecal 
stains  which  would  be  rendered  indelible  if  the  soiled  articles 
were  exposed  at  once  to  steam  or  boiling  water. 

Chloride  of  lime  in  0.5  per  cent,  cold-water  solution  may 
be  substituted  for  the  above  mixture,  but  as  it  has  some 
bleaching  effect  had  better  be  used  only  on  white  clothing. 
In  the  writer's  experiments  corrosive  sublimate  in  1  :  lOOO 
solution  has  almost  as  great  an  influence  in  rendering  blood 
and  fecal  stains  indelible  as  does  hot  water  at  from  176°  F, 
to  the  boiling  point.^ 

Clothing. — The  outer  clothing  of  the  attendants  should 
always  be  protected  by  a  cotton  slip  or  coat  that  reaches 
from  the  neck  to  the  floor.  This  coat  or  slip  should  always 
be  worn  when  the  attendant  is  on  duty.  At  the  end  of  the 
day  it  should  be  immersed  in  either  of  the  solutions  named 
above,  after  which  it  may  be  boiled  or  steamed  and  laun- 
dered. All  other  infected  clothing  should  be  packed  in 
tightly-closing  canvas  bags  and  conveyed  to  the  regular 
disinfecting  station  to  be  disinfected  by  steam. 

Where  such  stations  are  not  accessible,  one  may  have 
recourse  to  the  vapors  of  formaldehyde.  The  clothing 
should  be  hung  loosely  in  a  closet ;  a  lamp  for  decomposing 
paraformaldehyde  tablets  should  be  procured,  and  tablets 
should  be  decomposed  in  the  proportion  of  75  per  1000  cu. 
ft.  of  space  in  the  closet.  The  door  must  be  closed  during 
the  process  and  should  be  kept  closed  for  twenty-four  hours 
afterward.     This  is  not  as  certain  as  steam,  and  is  slightly 

'  See  7 rails.  Internat.  Congress  of  Charities,  Correction,  and  PkilantJiyopy\ 
Chicago,  June  12  to  18,  1893. 


PRECAUTIONS  IN  COMMUNICABLE  DISEASES.       295 

dangerous  because  of  the  fire,  but  is  to  be  recommended  for 
domestic  use  when  steam  is  not  available.  Infected  articles 
may  also  be  sprayed  with  a  4  per  cent,  formalin  solution, 
though  this  is  less  trustworthy  than  where  the  nascent  gas  is 
used. 

The  attendant  should  also  be  provided  with  loosely-fitting 
carpet  overshoes  that  should  be  repeatedly  disinfected  by 
steam. 

Whenever  the  attendant  has  occasion  to  leave  the  ward  or 
room,  both  the  slip  and  overshoes  should  be  left  in  the  room 
at  a  point  close  to  the  door  of  exit,  so  that  they  are  in  easy 
reach  when  he  returns. 

The  attendant  should  bathe  as  frequently  as  once  a  day, 
and  his  hands,  face,  beard  and  hair  should  be  frequently 
rinsed  in  a  i  :  5000  solution  of  bichloride  of  mercury,  or  a  i 
per  cent,  solution  of  carbolic,  or  a  i  per  cent,  solution  of 
chloride  of  lime. 

A  solution  that  is  suitable  for  sponging  the  entire  body, 
both  of  patient  and  attendant,  is  one  consisting  of  i  part 
Labarraque's  solution  to   19  of  water. 

Disinfection  of  Stools  and  Sputum. — The  stools  of 
all  patients  suffering  from  infective  intestinal  disorders,  such 
as  typhoid  fever,  cholera,  dysentery,  intestinal  tuberculosis, 
etc.,  should  be  disinfected  as  soon  as  they  are  passed ;  and 
this  should  constitute  a  part  of  the  routine  duty  of  the  nurse 
in  attendance.  Since  it  is  a  simple  process,  there  is  no 
excuse  for  its  not  being  regularly  and  faithfully  carried  out. 
It  is  the  most  important  step  in  preventing  the  spread  of 
these  maladies,  for  they  are  disseminated  wholly  and  alone 
through  the  living  infective  matters  that  are  passed  from  the 
bowels  and  kidneys  of  individuals  suffering  from  them. 

If  each  evacuation,  including  the  urine,  from  every  case  of 
typhoid  fever,  for  instance,  were  disinfected  as  soon  as  passed 
from  the  patient,  it  is  safe  to  say  that  this  disease  would  soon 
disappear  in  large  measure  from  among  us. 

Methods. — Mix  with  each  evacuation  double  its  volume  of 
freshly-prepared  milk  of  lime,  or  double  its  volume  of  i  per 
cent,  chloride-of-lime  solution,  or  double  its  volume  of  5  per 


296  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

cent,  carbolic-acid  solution ;  or  pour  upon  the  evacuation 
three  times  its  volume  of  boilbig  water  or  boiling  2  per  cent, 
soda  solution.  In  either  case  cover  the  vessel  and  allow  it 
to  stand  in  a  safe  place  for  from  one  to  two  hours  before  it  is 
emptied  into  the  closet. 

What  is  said  in  regard  to  intestinal  evacuations  applies 
equally  well  to  urine,  vomited  matters,  pus,  etc. 

Sputum. — Sputum  from  tuberculosis,  influenza,  and  pneu- 
monia patients  should  be  received  in  covered  vessels  contain- 
ing either  a  5  per  cent,  carbolic-acid  solution,  2  per  cent, 
tricresol  solution,  or  a  i  per  cent,  chloride-of-lime  solution. 
Or  they  may  be  spat  into  covered  receptacles  containing 
moist  sawdust  which,  with  their  contents,  are  afterward  dis- 
infected (at  the  end  of  each  day)  in  a  steam  sterilizer  and  the 
contents  finally  burned.  Or  it  may  be  received  in  cheap, 
pasteboard  receptacles  that  with  their  contents  may  be 
burned  at  the  end  of  each  day. 

Room  Disinfection. — There  is  as  yet  no  single  proced- 
ure by  which  every  article  in  an  ordinarily  furnished  infected 
room  may  be  simultaneously  and  certainly  disinfected. 

It  is  always  advisable  therefore,  where  circumstances  per- 
mit, to  have  but  little  unnecessary  furniture,  hangings,  car- 
pets, etc.,  in  rooms  occupied  by  the  sick.  For  rendering 
rooms  that  have  been  occupied  by  persons  suffering  from 
contagious  diseases  free  from  danger,  the  most  trustworthy 
plan  consists  in  a  combination  of  the  best  features  of  several 
methods  that  have  been  from  time  to  time  proposed. 

The  steps  to  be  taken  are  briefly  as  follows  :  After  the 
room  has  been  vacated  by  the  patient,  all  conspicuous  cracks 
and  crevices  should  be  sealed,  the  door  should  be  closed  and 
locked,  and  the  room  kept  closed  for  at  least  twenty-four 
hours.  At  the  end  of  this  time  formaldehyde  gas  should  be 
either  generated  in  the  room  by  the  decomposition  by  heat 
of  from  50  to  75  tablets  of  polymerized  formaldehyde  to  each 
1000  cu.  ft.  of  air-space,  or  formaldehyde  gas  generated  from 
its  watery  solution  by  an  approved  apparatus  may  be  passed 
into  the  room  from  without.  The  amount  of  gas  employed 
should  be  that  given  off  fron^.  at  least  i  pound  of  formalin  or 


PRECAUTIONS  IN  COMMUNICABLE   DISEASES.       297 

formochloral  for  each  lOOO  to  1200  cu.  ft.  of  air-space  (see 
Formaldehyde). 

After  this  the  room  should  be  kept  closed  for  at  least  six 
hours.  This  accomplishes  the  necessary  disinfection  of  all 
surfaces. 

The  room  may  then  be  entered  and  all  bed-clothing,  pil- 
lows, mattresses,  other  clothing  in  closets,  chests,  trunks, 
etc.,  should  be  put  into  canvas  bags,  brought  for  the  purpose 
by  the  operators,  and  sent  at  once  to  a  disinfecting  station, 
where  they  are  subjected  to  the  action  of  steam.  This  com- 
pletes the  disinfection  of  those  articles  that  were  only  super- 
ficially acted  upon  by  the  formaldehyde  gas. 

In  the  meantime  the  ceiling  and  walls  are  to  be  wiped  down 
with  cloths  wrung  out  in  3  per  cent,  carbolic-acid,  i  :  2000 
corrosive-sublimate,  or  0.5  per  cent,  chloride-of-lime  solution  ; 
and  finally,  all  furniture  and  all  horizontal  surfaces,  such  as 
window-sills,  cornices,  etc.,  are  to  be  similarly  wiped  off,  after 
which  the  floor  is  to  be  scrubbed  with  hot  soda  solution  of 
about  4  per  cent,  strength. 

In  the  case  of  hangings,  valuable  curtains,  tapestries,  car- 
pets, etc.,  that  might  be  injured  by  steam  disinfection,  it  is 
best  to  remove  them  after  the  action  of  the  formaldehyde  and 
have  them  thoroughly  beaten  or  shaken  on  some  distant 
open  lot,  after  which  they  should  be  freely  exposed  to  direct 
sunlight. 

The  object  of  each  of  these  steps  is : 

The  keeping  of  the  room  closed  for  a  day  after  its  vacation 
permits  all  dust  to  settle. 

The  generation  of  formaldehyde  gas  in  the  room  disinfects 
the  dust  and  all  exposed  surfaces,  so  that  there  is  danger 
neither  to  the  operators  themselves  nor  of  their  conveying 
infective  matters. 

The  wiping  of  walls,  furniture,  and  surfaces,  and  the  scrub- 
bing of  the  floors  with  disinfecting  solutions  insures  the  de- 
struction of  infective  matters  that  may  have  escaped  the  action 
of  the  formaldehyde  gas. 

The  steaming  of  pillows,  mattresses,  bed-clothing,  etc.,  in- 
sures the  destruction  of  infective  matters  that  may  have  soaked 


298  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

into  their  deeper  layers  and  escaped  the  action  of  the  formal- 
dehyde gas. 

In  some  places  sulphur  dioxide  gas  is  employed  in  place 
of  formaldehyde  and  is  often  the  only  step  taken  for  disinfec- 
tion, but  it  is  doubtful  if  the  results  are  ever  as  satisfactory  or 
as  complete  as  when  formaldehyde  is  properly  used. 

Again,  the  walls  and  surfaces  are  sometimes  rubbed  over 
with  gluten  bread,  to  which  all  dust  and  infective  particles 
adhere,  after  which  the  bread  is  burned.  This  has  no  ad- 
vantage over  the  cloths  rung  out  in  reliable  disinfectant  so- 
lutions. 

When  a  room  has  been  disinfected  and  cleaned  by  the  proc- 
ess outlined  above,  it  should  be  thoroughly  aired  for  a  few 
days  before  it  is  occupied. 

On  closing  the  room  preparatoiy  to  its  disinfection,  the 
nurse  or  attendant  whose  duties  it  has  been  to  seal  up  all 
cracks  and  crevices,  before  leaving  should  doff  her  over-slip 
and  overshoes  and  leave  them  in  the  room  to  be  disinfected 
with  the  other  articles. 

(See  personal  experience  in  room  disinfection  with  formal- 
dehyde under  "  Formaldehyde.") 

Care  of  the  Body  after  Death. — It  is  ordinarily  ad- 
visable that  the  cadavers  of  patients  who  have  died  of  the 
most  dangerous  communicable  diseases  be  at  once  enveloped 
in  a  sheet  saturated  with  either  5  per  cent,  carbolic-acid,  4 
per  cent,  chloride-of-lime,  or  i  :  1000  solution  of  corrosive 
sublimate,  and  placed  at  once  in  the  coffin  in  which  each  is 
to  be  buried. 

These  cadavers  should  be  buried  as  soon  as  decency  per- 
mits. The  law  should,  and  usually  does,  forbid  public  funer- 
als in  these  cases. 

With  the  less  dangerous  infectious  diseases,  however,  such 
stringent  measures  are  not  observed.  The  body  after  death 
may  be  washed  in  either  of  the  strong  disinfecting  solutions 
mentioned,  though  because  of  their  odor  the  carbolic-acid 
and  chloridc-of-lime  solutions  usually  give  way  to  the  subli- 
mate solution. 

The  rectum  in  those  cases  of  intestinal  infection  should  be 


QUARANTINE.  299 

tightly  plugged  with  cotton  soaked  in  the  sublimate  or  car- 
bolic solution,  and  as  soon  as  practicable  the  body  should  be 
placed  in  the  coffin  in  which  it  is  to  be  buried. 

It  is  not  advisable,  even  in  the  milder  infective  cases,  to  ex- 
pose the  remains  in  open  caskets.  The  body  should  be 
buried  or  cremated ;  the  results  of  the  two  processes  of  final 
disposal  differing,  as  a  rule,  only  in  the  time  required  for  their 
accomplishment.  If  buried,  the  place  selected  should  be  so 
located  as  not  to  endanger  neighboring  drinking-water  sup- 
plies. 


QUARANTINE. 

Quarantine  may  be  defined  as  the  segregation  or  isolation 
of  such  persons  and  objects  as  may  be  a  menace  to  the  health 
of  the  surrounding  community,  though  the  common  usage 
of  the  term  refers  more  to  the  enforced  detention  at  ports  of 
entry  of  persons,  personal  effects,  and  articles  of  merchan- 
dise coming  by  land  or  sea  from  localities  in  which  danger- 
ous epidemic  diseases  are  in  existence,  to  localities  that  are 
free  from  them. 

Its  object  is  to  prevent  the  importation  and  dissemination 
of  infectious   maladies. 

In  its  original  meaning  it  implied  the  detention  for  forty 
days,  this  being  regarded  as  the  period  necessary  for  the 
"  self-consumption  "  of  the  morbific  agents  of  acute  epidemic 
diseases.  In  its  modern  usage,  however,  the  word  refers 
more  to  the  process  than  to  the  time  of  its  enforcement,  the 
latter  feature  having  been  modified  to  meet  the  exigencies  of 
particular  cases  ;  that  is  to  say,  there  is  no  longer  a  fixed 
period  of  detention  for  all  cases,  but  the  length  of  this  period 
varies  according  to  the  period  of  incubation  of  the  particular 
disease  against  the  importation  of  which  the  precaution  is 
being  taken. 

In  England  there  is  a  tendency  to  eliminate  entirely  the 


300  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

enforced  detention,  the  authorities  preferring  to  rely  more 
upon  the  prompt  notification  of  outbreaks  of  contagious  dis- 
ease and  upon  measures  that  aim  to  place  their  ports  of 
entry  in  such  sanitary  condition  that  epidemic  diseases  can- 
not gain  a  foothold,  than  upon  the  systems  of  quarantine  as 
usually  enforced. 

Because  of  the  serious  embarrassment  to  commercial  inter- 
course that  the  older  methods  of  quarantine  entailed,  and 
because  of  the  demonstrated  inadequacy  to  close  all  chan- 
nels of  intercourse  completely  by  such  methods,  numerous 
congresses  of  experts  have  convened  for  the  purpose  of 
formulating  a  more  expeditious  and  trustworthy  system  for 
the  management  of  suspicious  and  dangerous  matters  arriv- 
ing from  infected  districts.  Though  no  uniform  plan  has 
been  adopted  as  a  result  of  these  debates,  still  it  is  evident 
that  the  tendency,  briefly  stated,  is  to  depart  very  widely 
from  the  practices  of  former  years  and  to  rely  more  upon 
the  prompt  enforcement  of  active,  trustworthy,  sanitary  meas- 
ures than  upon  the  uncertain  element  of  detention. 

Briefly  summarized,  such  measures  comprise : 

Strict  sanitary  supervision  of  all  ports  of  entry  ;  the  board- 
ing and  inspection  of  all  vessels  arriving  from  foreign  ports, 
and  in  special  cases  of  all  vessels,  from  domestic  as  well  as 
foreign  ports.  This  latter  is  enforced  when  epidemic  diseases 
existing  in  one  part  of  a  country  are  liable  to  be  conveyed  to 
another  by  means  of  maritime  commerce. 

The  disinfection,  fumigation,  and  cleansing  of  all  ships  found 
upon  inspection  to  be  possible  causes  of  infection. 

The  removal  from  the  ships  to  the  hospital  of  the  station 
of  all  passengers  and  crew  found  to  be  infected  ;  also  the 
removal  to  pavilions  of  observation  of  all  other  individuals 
from  the  ship  and  their  detention  for  a  period  of  time  neces- 
sary to  determine  whether  they  are  themselves  infected  or  not. 

The  registration  of  all  incoming  persons,  including  the 
statement  as  to  whence  they  come  and  whither  they  are 
going,  and  the  compulsoiy  notification  of  the  authorities  of 
any  form  of  contagious  disease  that  may  appear  among  such 
persons  cither  cii  route  to  or  after  reaching  their  destination. 


QUARANTINE.  3OI 

The  careful  disinfection  of  the  clothing  and  other  personal 
effects  of  the  passengers  and  crews  from  infected  ships. 

The  removal  and  disinfection  of  the  cargo  or  ballast  from 
suspected  ships  or  from  ships  coming  from  infected  ports  and 
believed  to  be  infected. 

The  reg-ular  notification  of  the  chief  of  the  national  or 
state  quarantine  service,  by  the  quarantine  officer  in  charge, 
of  all  pertaining  to  the  ship  under  consideration,  with  a  full 
description  of  the  steps  taken  to  render  her  free  from  danger. 

The  giving  of  free  pratique  to  the  ship,  as  soon  as  circum- 
stances will  permit,  after  she  has  been  subjected  to  the  meth- 
ods of  cleansing  and  disinfection  deemed  proper  by  the  quar- 
antine authorities. 

To  carry  out  this  work  properly  it  is  necessary  that  the 
quarantine  station  be  under  the  management  of  a  staff  of 
trained  officers  who  are  fully  impressed  with  the  importance 
of  their  work. 

They  should  have,  at  their  disposal  a  corps  of  assistants 
who  have  been  thoroughly  instructed  in  the  duties  that  they 
are  to  perform. 

The  station  should  be  located  at  a  place  of  safe  anchorage, 
convenient  to  the  channel  of  traffic,  but  sufficiently  removed 
from  populous  centers  and  from  the  line  of  travel  to  prevent 
its  being  a  source  of  danger  to  the  surrounding  community 
and  to  non-infected  vessels  and  to  their  crews. 

The  station  should  be  provided  with  the  necessary  boats, 
launches,  or  tugs  for  boarding  in  all  weathers. 

It  should  be  provided  with  a  steam-disinfecting  plant  of 
approved  pattern  for  the  disinfection  of  articles  of  clothing 
and  of  merchandise  that  may  be  brought  on  shore  ;  with 
tanks  for  holding  disinfecting  solutions  that  are  to  be  used  on 
shore  ;  with  facilities  for  the  bathing  and  personal  disinfection 
of  all  suspected  passengers  and  crews  from  infected  vessels  ; 
with  a  detention-pavilion  for  the  observation  of  persons  from 
infected  ships  who  are  themselves  at  the  time  of  quarantine 
not  actually  sick  of  the  disease  against  which  the  ship  is  being 
quarantined ;  with  properly  equipped  hospitals  or  pavilions 
for  the  treatment  of  all  cases  of  contagious  disease. 


302  HYGIENE    OF  TRANSMISSIBLE  DISEASES. 

The  general  sanitary  condition  of  the  station  as  regards 
water-supply,  food-supply,  and  drainage,  heating  and  venti- 
lation of  barracks,  etc.,  should  be  of  the  best. 

All  officers  and  assistants  should  have  been  vaccinated 
against  small-pox,  and  for  stations  having  frequently  to  do 
with  yellow  fever,  it  is  advisable  to  select  the  staff  from  among 
individuals  who  have  already  had  the  disease. 

There  should  be  a  rigid  isolation  of  the  hospital  and  deten- 
tion-pavilions and  their  nurses  and  attendants  from  other  build- 
ings and  persons  of  the  station. 

For  the  expeditious  disinfection  of  ships'  holds  and  cabins 
the  station  should  be  provided  with  a  steam-vessel  fully 
equipped  with  provisions  for  generating  the  fumigating  gases 
in  large  quantities,  for  the  liberation  of  hot  water  or  steam 
under  pressure,  and  with  pumps  for  the  forcible  ejection  of 
of  disinfectants  to  be  used  in  cleansing  and  disinfecting  the 
ship. 

There  should  be  a  crematory  for  the  disposal  by  fire  of  all 
useless  articles  that  may  harbor  infection. 

In  addition  to  maritime  quarantine,  to  which  the  above 
particularly  refers,  we  hear  of  other  kinds  of  quarantine, 
though  they  differ  from  one  another  only  in  their  application 
to  different  channels  through  which  infection  may  be  imported 
or  spread,  the  object  throughout  being  the  same.  Thus,  for 
example,  we  hear  of  "  railroad  quarantine,"  meaning  the 
sanitary  supervision  of  persons  and  articles  of  merchandise 
arriving  by  rail  from  infected  localities.  In  its  mode  of  ap- 
plication it  is  essentially  the  same  as  maritime  quarantine ; 
of  "  house  quarantine,"  meaning  the  prevention  of  inhabitants 
of  infected  houses  from  mingling  with  the  general  public,  as 
well  as  the  prevention  of  outside  persons  from  visiting  such 
houses  unless  duly  authorized  ;  of  the  "  sanitary  cordon," 
sometimes  known  popularly  as  "  shot-gun "  quarantine, 
meaning  a  system  of  isolation,  sometimes  unauthorized,  that 
is  conducted  by  surrounding  infected  districts  with  a  cordon 
of  armed  patrols  who  are  instructed  to  prevent,  by  force  if 
necessary,  all  communication  between  the  suspicious  focus 
and  the  surrounding  countiy. 


QUARANTINE.  3O3 

In  addition,  we  hear  of  systems  of  quarantine  against  cer- 
tain specific  diseases,  as  "  yellow-fever  quarantine,"  "  cholera 
quarantine,"  "  diphtheria  quarantine,"  indicating  at  once  the 
particular  measures  that  are  in  force  to  check  the  spread  of 
this  or  that  disease. 

While  maritime  quarantine  is  of  necessity  an  elaborate 
process,  as  carried  out  at  our  great  ports  of  entry,  it  is  far 
more  easy  to  conduct  it  consistently  and  with  advantage  to 
the  public  health  than  is  inland  quarantine.  In  the  latter 
event  the  channels  of  intercourse  are  so  numerous  that  their 
complete  obstruction  is  a  matter  of  practical  impossibility. 
It  is  here  that  the  importance  of  an  adequate  system  of  noti- 
fication of  contagious  diseases  is  seen,  for  it  is  only  by  this 
means  that  outbreaks  within  our  borders,  originating  through 
importation,  can  be  early  recognized,  and  receive  the  sanitary 
supervision  that  their  gravity  demands. 

Quarantine  was  originally  established  to  guard  against  the 
spread  of  the  plague,  but  as  time  went  on  it  was  employed 
against  additional  contagious  diseases,  one  after  another,  un- 
til at  the  present  time  it  may  be  practised  against  practically 
all  communicable  diseases,  though  cholera,  typhus  fever,  yel- 
low fever,  small-pox,  and  leprosy  are  the  maladies  against 
which  it  is  conspicuously  employed.  It  is,  however,  the 
opinion  of  those  versed  in  the  subject  that  all  immigrants 
suffering  from  such  diseases  as  the  acute  exanthemata,  dys- 
entery, glanders,  beriberi,  epidemic  influenza,  and  in  fact  all 
communicable  diseases,  should  be  detained  for  a  time  neces- 
sary to  place  them  beyond  the  point  of  danger  to  those  with 
whom  they  may  come  in  contact. 

Note. — For  details  relating  to  the  practice  of  quarantine  in  the  United 
States,  see  the  excellent  publications  of  the  Marine  Hospital  Service,  notably  : 

"Quarantine  Laws  and  Regulations  of  the  United  States,"  Treasury  De- 
partment, Document  No.  1677,  Marine  Hospital  Service. 

"  A  Precis  of  Quarantine  Practice  at  National  Quarantine  Stations,"  pre- 
pared by  Passed  Assist.  Surgeon  H.  D.  Geddings  :  Reports  of  U.  S.  Marine 
Hospital  Service,  1896,  pp.  479-523. 


INDEX. 


Acclimatization,  255 
Acids  as  disinfectants,  275 
Acquired  immunity,  241 

transmissibility  of,  from  parent  to 
child,  253 
Actinomyces,  171 
Actinomycosis,   17 1 
cause  of,  171 
dissemination  of,  173 
portal  of  infection  in,  173 
prophylaxis  against,  174 
Active  immunity,  250 
Acute  croupous  pneumonia,  107.     See 

also  Pneumonia. 
Age  as  a  predisposing  cause  of  disease, 

27 
Amoeba  dysenterise,  97 
Amoebic  dysentery,  97 
cause  of,  97 
distribution  of,  98 
mode  of  dissemination  in,  98 
portal  of  infection  in,  99 
prophylaxis  against,  99 
Anesthetic  leprosy,  148 
Animal  parasites  as  a  cause  of  disease, 

53 
diseases  due  to,  223 
Animal  resistance,  26 
Ankylostomiasis,  225 
Anthrax,  160 
bacillus  of,  160 
cause  of,  160 
external,  163 
in  man,  162 
internal,  164 
prophylaxis  against,  164 
Antiseptic,  260 

Antitoxic  condition,  245,  et  seq. 
20 


Apartments,  disinfection  of,  208 
Ascaris  lumbricoides,  224 
Asiatic  cholera,  89 

bacillus  of,  89 

care  of  dead  after,  96 

cause  of,  89 

distribution,  season,  race,  etc.,  91 

mode  of  dissemination  in,  92 

portals  of  infection  in,  94 

prophylaxis  against,  95 
Attendants,  clothing  of,  294 
Autoclaves   for  generating    formalde- 
hyde, 265 

Bacillus  anthracis,  160 

diphtherise,  ixi 

icteroides,  203 

influenzae,  124 

leprae,  148 

mallei,  166 

of  Asiatic  cholera,  89 

of  bubonic  plague,  127 

of  glanders,  166 

of  syphilis,  I41 

of  typhoid  fever,  63 

of  whooping  cough,  187 

of  yellow  fever,  203 

tetani,  155 

tuberculosis,  100 

typhosus,  63 

X,  203 
Bacteria  as  causes  of  disease,  54 

effect  of  desiccation  on,  288 
of  electricity  on,  289 
of  mechanical  agitation  on,  290 
of  sunlight  on,  288 
Beef  tape-worm,  237 
Bichloride  of  mercury,  272 

305 


3o6 


INDEX. 


Black  death,  128 

vomit,  202 
Body,  care  of,  after  death,  298 
Boiling,  disinfection  by,  283 
Bothriocephalus  latus,  238 
Breakbone  fever,  208.     See  Dengue. 
Brick-makers'  anemia,  225 
Bromine,  263 
Bubonic  plague,  126 

cause  of,  126 

dissemination  and  modes  of  infec- 
tion in,  130 

distribution,  race,  season,  etc.,  128 

prophylaxis  against,  131 

Cadaver,  care  of,  after  death,  298 
Camp  fever,  211 
Carbolic  acid,  269 
Carbol-soap  solution,  27 1 
Carbol-sulphuric  acid,  270 
Care  of  body  after  death,  298 
Causation  of  disease,  25 
Causes  of  disease,  chemical,  52 
exciting,  51 
mechanical,  53 
physical,.  53 
predisposing,  26 
vital,  53 
Caustic  ammonia,  275 
potassa,  275 
soda,  275 
Cellars,  disinfection  of,  279 
Cerebrospinal  fever,  118 
meningitis,  epidemic,  118 

age,  season,  mortality,  etc.,  120 
cause  of,  1 18 
distribution  of,  119 
history  of,  119 

modes  of  dissemination  in,  121 
portal  of  infection  in,  I2I 
prophylaxis  against,  123 
Cestodes,  233 

Chemical  causes  of  disease,  52 
disinfection,  259,  261 
special,  277 
Chicken-pox,  180.     See  also  Varicella. 
Chloride  of  lime,  273 


Chlorine,  263 

Chlorosis,  Egyptian,  225 

Cholera,  Asiatic,  89 

care  of  dead  after,  96 

cause  of,  89 

distribution,  season,  race,  etc.,  91 

mode  of  dissemination  in,  92 

portals  of  infection  in,  94 

prophylaxis  against,  95 

Cisterns,  disinfection  of,  280 

Clothing  of  attendants,  294 

Comma  bacillus,  89 

Contagious  diseases  defined,  55 

Cordon,  sanitary,  302 

Creolin,  272 

Cresols,  271 

Crowding  as  a  predisposing  cause  of 
disease,  41 

Cysticercus  cellulosEe,  235 

Dandy  fever,  208.     See  Dengue. 
Death,  care  of  body  after,  298 
Death-rate,  relation  of,  to   density  of 
population,  41 

of  whites  and  negroes  compared,  33 
Dengue,  208 

dissemination  of,  210 

prophylaxis  against,  2IO 
Density  of  population  and  death-rate, 

41 
as  a  predisposing  cause  of  disease, 

41 

Deodorizer,  260 

Desiccation,  effect  on  bacteria,  288 

Diarrheal    diseases,    monthly    fluctua- 
tions in  death-rates  from,  48 

Diphtheria,  iii 
bacillus  of,  III 
cause  of,  1 1 1 

distribution,  season,  age,  etc.,  113 
modes  of  dissemination  in,  113 
monthly  variation  in  death-rate  from, 

portals  of  infection  in,  1 15 
prophylaxis  against,  1 16 
Diplococcus    intracellularis  meningiti- 
dis,  118 


INDEX. 


307 


Direct  causes  of  disease,  51 
Disease,  causation  of,  24 

exciting  causes  of,  51 

predisposing  causes  of,  26 
Disinfectants,  260 

bichloride  of  mercury,  272 

bromine,  263 

carbolic  acid,  269 

carbol-soap  solution,  271 

carbol-sulphuric  acid,  270 

caustic  ammonia,  275 

caustic  potassa,  275 

caustic  soda,  275 

chloride  of  lime,  273 

chlorine,  263 

creolin,  272 

cresols,  271 

formaldehyde,  263 

formalin,  264 

hydrochloric  acids,  275 

milk  of  lime,  274 

permanganate  of  potash,  276 

silver  nitrate,  273 

soda  solutions,  275 

sulphate  of  iron,  276 

sulphur  dioxide,  262 

sulphuric  acid,  276 

tricresol,  271 
Disinfection,  259 

by  boiling,  283 

by  dry  heat,  283 

by  fire,  282 

by  heat,  282 

by  physical  processes,  282 

by  steam,  283 

chemical,  261 

of  apartments,  208 

of  cellars,  279 

of  cisterns,  280 

of  evacuations,  277 

of  hands,  281 

of  privy  vaults,  277 

of  rooms,  296 

of  ships,  301 

of  sinks,  278 

of  sputum,  296 

of  stables,  279 


Disinfection  of  stools,  295 

of  urinals,  278 

of  water-closets,  278 

of  wells,  280 

special  chemical,  277 
Dracontiasis,  226 
Dracunculus  medinensis,  226 
Drying,  effect  of,  on  bacteria,  288 
Dust-inhalation,  effect  of,  38 
Dysentery,    amoebic,    97.      See     also 
Atncebic  Dysentery. 

tropical,  97 

Earth  as  a  deodorizer,  276 
Echinococcus  hominis,  238 
Ectogenous  causes  of  disease,  52 
Egyptian  chlorosis,  225 
Electricity,  effect  of,  on  bacteria,  289 
Endogenous  causes  of  disease,  52 
Epidemic     cerebrospinal     meningitis, 

118 
Evacuations,  disinfection  of,  277 
Exciting  causes  of  disease,  51 

chemical,  52 

mechanical,  53 

physical,  53 

vital,  53 

Facultative  parasite,  60 

saprophyte,  60 
Famine  fever,  214 
Farcy,  166 

Fever,  malarial,  189.     See  also  Mala- 
rial Fever. 
relapsing,      214.       See      Relapsing 

Fever. 
scarlet,  182.     See  also  Scarlet  Fever. 
typhoid,    63.      See    also     Typhoid 

Fever. 
typhus,  211.     See  Typhus  Fever. 
yellow,  202.     See  also  Yellow  Fever. 
Filaria  medinensis,  226 
sanguinis  hominis,  227 
diurna,  229 
nocturna,  229 
perstans,  229 
Filariasis,  227 


3o8 


INDEX. 


Filtration  of  water  in  Hamburg,  effect 
on  cholera,  92 
effect  on  typhoid  fever,  88 
Fire,  disinfection  by,  282 
Focal  zone  of  yellow  fever,  204 
Formaldehyde,  263 
Formalin,  263 
Formic  aldehyde,  263 
Fungus  disease  of  India,  174.    See  also 

Aladura  Foot. 
P'urbringer's    method    of    disinfecting 
hands,  281 

Garden  earth  as  a  deodorizer,  276 
German  measles,  181 
Glanders,  166 

bacillus  of,  166 

cause  of,  166 

modes  of  dissemination,  169 

portals  of  infection,  169 

prophylaxis  against,  170 
Gonococcus,  140 
Gonorrhoea,  140 

dissemination  of,  142 

modes  of  infection  in,  142 

prophylaxis  against,  143 
Great  Plague  of  London,  129 
Guinea-worm,  226 

Hamburg,  cholera  in,  92 

typhoid  fever  in,  before  and  after 
filtration,  88 
Hands,  disinfection  of,  281 
Heat,  disinfection  by^  282 
Heredity  as  a  predisposing  cause  of 

disease,  45 
Hospital  fever,  211 
Houses  of  various  sizes,  death-rate  in, 

42,43 
Hydrochloric  acid,  275 
Hydrophobia,  216.     See  also  Rabies. 
Hygiene,  definition  of,  17 

Immunity,  241 
active,  250 
acquired,  24 1 
natural,  253 


Immunity,  passive,  250 

transmissibility    of,    from    parent    to 
offspring,  253 
Infections,    suppurative    and      septic, 

133 

Infectious  diseases,  defined,  55 

general  prophylaxis  against,  241 
Influenza,  124 

bacillus  of,  124 

cause  of,  124 

dissemination  of,  125 

mode  of  infection  in,  126 

occurrence,  distribution,  etc.,  1 25 

prophylaxis  against,  126 
Inoculation,  protective,  242 
Intermittent  malarial  fever,  189 
Isolation,  291 

Jail  fever,  211 

Jews,  mortality  among,  35,  36 

Kny-Sprague  disinfector,  285 
Koch's  postulates,  56 

Labarraque's  solution,  274 
Lausen  epidemic  of  typhoid  fever,  70 
Lepra-cells,  149 
Leprosy,  148 

bacillus  of,  148 

cause  of,  148 

dissemination  of,  151 

geographical  distribution,  race,  etc., 
150 

modes  of  infection  in,  151 

prophylaxis  against,  153 
Liquor  dealers,  comparative  mortality 

of,  38 
Liquor  sodte  chlorinatse,  274 
Lobar    pneumonia,     107.       See     also 

Pnetivionia,  acute  croupous. 
Lock-jaw,  155.     See  also  Tetanus. 
Louis's  law,  27 
Lumpy  jaw,  172 
Lyssa,  216.     See  also  Rabies. 

Madura  foot,  174 
etiology  of,  175 


INDEX. 


309 


Malarial  fever,  189 
cause  of,  189 
chart    of    monthly    variation     in 

death-rate  from,  49 
conditions    influencing     develop- 
ment of,  197 
geographical  distribution  of,  196 
influence  of  air-currents  on,  199 
of  rainfall  on,  198 
of  season  on,  199 
intermittent,  189 
marsh  land  and,  197 
modes  of  infection  in,  200 
prophylaxis  against,  201 
remittent,  189 
Malignant  anthrax  edema,  163 

pustule,  163 
Measles,  181 
cause  of,  181 
German,  181 
Mechanical  agitation,  effect  of,  on  bac- 
teria, 290 
causes  of  disease,  53 
Metacresol,  271 

Miasmatic  diseases,  defined,  55 
Micrococcus  gonorrhoeae,  140 

lanceolatus,  107 
Milk-epidemics  of  diphtheria,  115 
Milk  of  lime,  274 
Miners'  cachexia  or  chlorosis,  225 
Mumps,  188 
Mycetoma,    174.      See    also    Madura 

Foot. 
Mycosis  intestinalis,  164 
Natural  immunity,  253 

Negroes,  death-rate  among,  33 
Nematoda,  224 

Novy-Waite    formaldehyde  generator, 
266 

Obligate  parasite,  60 

saprophyte,  60 
Occupation  as  a  predisposing  cause  of 

disease,  37 
Occupations,  comparative  mortality  in 

different,  40 


Orthocresol,  271 
Oxyuris  vermicularis,  224 

Paracresol,  271 

Parasite,  definition  of,  59 

Parasites,  animal,  as  a  cause  of  disease, 

53 
diseases  due  to,  223 
facultative,  60 
obligate,  60 
Passive  immunity,  250 
Perifocal  zone  of  yellow  fever,  204 
Permanganate  of  potash,  276 
Pertussis,    186.      See    also     Whooping 

cough. 
Philadelphia,  typhoid  epidemic  at,  82 
Physical  cause  of  disease,  53 
Plague,  bubonic,  126 
bacillus  of,  127 

dissemination   and   modes  of  in- 
fection, 130 
distribution,  race,  season,  128 
prophylaxis  against,  131 
Plasmodium  malariae,  189 
crescentic  forms  of,  195 
flagellated  varieties  of,  194 
Plymouth,    Pa.,    epidemic    of  typhoid 

fever  at,  78 
Pneumococcus,  107 
Pneumonia,  acute  croupous,  107 
cause  of,  107 

distribution,  age,  sex,  etc.,  108 
modes  of  dissemination  of,  109 
portal  of  infection  in,  1 10 
prophylaxis  against,  1 10 
Population,  density  of,  41 
Pork  tape-worm,  234 
Predisposing  causes  of  disease,  26,  31, 

37 

age,  27 

density  of  population,  4I 

heredity,  45 

season,  47 

sex,  29 
Privy  vaults,  disinfection  of,  277 
Prophylactic   measures,    chemical  and 

physical,  259 


lO 


INDEX. 


Prophylaxis,  general,  against  infectious 

diseases,  241 
Protective  inoculation,  242 

Quarantine,  299 
Quartan  fever,  1 89 

Rabies,  216 
cause  of,  216 

preventive  inoculation  against,  220 
prophylaxis  against,  219 
symptoms  of,  218 
Race  as  a  predisposing  cause  of  dis- 
ease, 31 
Railroad  quarantine,  302 
Relapsing  fever,  214 

dissemination  of,  215 
distribution  of,  215 
prophylaxis  against,  215 
Remittent  malarial  fever,  189 
Respiratory  diseases,  monthly  fluctua- 
tions in  death-rate  from,  47 
Rhabdonema  intestinale,  226 
Room  disinfection,  296 
Rotheln,  181 
Round  worm,  224 
Rubeola,  181 

Sanitary  cordon,  302 
Saprophyte,  definition  of,  59 
Saprophytes,  facultative,  60 

obligate,  60 
Scarlatina,  monthly  variations  in  death- 
rate  from,  51 
Season  as  a  predisposing  cause  of  dis- 
ease, 47 
Seven  days'  fever,  214 
Sex  as  a  predisposing  cause  of  disease, 

29 
Scarlatina,  monthly  variations  in  death- 
rate  from,  51 
Scarlet  fever,  182 
cause  of,  182 
dissemination  of,  183 
prophylaxis  against,  184 
Ship  fever,  211 
Ships,  disinfection  of,  301 


Shot-gun  quarantine,  302 
Sick-room,  precautions  in,  292 
Silver  nitrate,  273 
Sinks,  disinfection  of,  278 
Small-pox,  176 

cause  of,  176 

dissemination  of,  177 

historical  sketch  of,  176 

prophylaxis  against,  178 
Soda  solutions,  275 
Species,  definition  of,  60 
Spirillum  cholerae  Asiaticse,  89 
Spirochseta  Obermeieri,  214 
Spotted  fever,  118.     See  Cerebrospinal 
Meningitis,  epide?7iic  ;  also  2 1 1 . 
Sputum,  disinfection  of,  296 

in  tuberculosis,  105 
Stables,  disinfection  of,  279 
Staphylococcus  epidermidis  albus,  134 

pyogenes  albus,  134 
aureus,  132 
citreus,  134 
Steam,  disinfection  by,  283 

-sterilizers,  283 
Stools,  disinfection  of,  295 
Streptococcus  pyogenes,  135 
Sulphate  of  iron,  276 
Sulphur  dioxide,  262 
Sulphuric  acid,  276 
Sulphurous-acid  gas,  262 
Sunlight,  effect  of,  on  bacteria,  288 
Suppurative  and  septic  infections,  133 
modes  of  dissemination,  136 
portal  of  infection,  138 
prophylaxis  against,  138 
Syphilis,  141 

bacillus  of,  141 

dissemination  of,  142 

modes  of  infection  in,  I42 

prophylaxis  against,  143 

T/ENIA  echinococcus,  239 

medio-canellata,  237 

saginata,  237 

solium,  234 
Taenise,  233 
Tape-worm,  233 


INDEX. 


311 


Tape-worm,  beef,  237 

pork,  234 
Tertian  fever,  189 
Tetanus,  155 
bacillus  of,  155 
cause  of,  155 
dissemination  of,  158 
distribution,  season,  race,  157 
modes  of  infection  in,  158 
prophylaxis  against,  159 
Thread  worm,  224 

Three  days'  fever,  208.     See  Dengue. 
Trichina  spiralis,  230 
Trichirosis,  230 
Trichocephalus  dispar,  224 
Tricresol,  271 
Tropical     dysentery,    97.       See     also 

Amcebic  Dysentery. 
Tuberculosis,  100 
bacillus  of,  100 
cause  of,  100 
definition  of,  100 
distribution,  race,  sex,  etc.,   loi 
mode  of  disserflination,  102 
portal  of  infection  in,  103 
prophylaxis   against,  105 
Tunnel  disease,  225 
Typhoid  fever,  63 
bacillus  of,  63 
cause  of,  63 
distribution,  69 
epidemic   at   Philadelphia,    1897- 

98,  82 
epidemic  of,  70 

at  Plymouth,  Pa.,  78 
Lausen  epidemic,  70 
mode  of  dissemination,  64 
monthly    variation    in    death-rate 

from,  50 
portal  of  infection,  66 
prophylaxis  against,  66 
Wittemburg  epidemic  of,  73 


Typhus  fever,  21 1 

dissemination  of,  212 
distribution  of,  21 1 
prophylaxis  against,  212 

Urinals,  disinfection  of,  278 

Vaccination,  242 
Varicella,  180 
cause,  180 

prophylaxis  against,  180 
Venereal  diseases,  140 
dissemination,  142 
modes  of  infection  in,  142 
prophylaxis  against,  143 
Vital  causes  of  disease,  53 
processes  of  immunity,  241 
resistance,  26 

Water-closets,  disinfection  of,  278 
Welch's    method    of    disinfecting    the 

hands,  282 
Wells,  disinfection  of,  280 
Whip-worm,^  224 
Whooping  cough,  186 

bacillus  of,  187 

cause,  186 

prophylaxis  against,  188 
Wittemburg  epidemic  of  typhoid  fever 

73 
Wooden  tongue,  172 

Yellow  fever,  202 

bacillus  of,  203 

dissemination  of,  206 

etiology  of,  203 

geographical  distribution  of,  204 

prophylaxis  against,  207 

race  susceptibility  to  and  immunity 
from,  205 

seasonal  and  geographical  influ- 
ences in,  206 


CATALOGUE 

OF   THE 

MEDICAL  PUBLICATIONS 

OF 

W.  B.  SAUNDERS, 

No.   925   WALNUT   STREET,   PHILADELPHIA. 


Arranged  Alphabetically  and  Classified  under  Subjects* 


THE  books  advertised  in  this  Catalogue  as  being  sold  by  subsciiption  are  usually  to  be 
obtained  from  travelling  solicitors,  but  they  will  be  sent  direct  from  the  office  of  pub- 
lication (charges  of  shipment  prepaid)  upon  receipt  of  the  prices  given..     All  the  other 
books  advertised  are  commonly  for  sale  by  booksellers  in  all  parts  of  the  United  States;  but 
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office  money  order,  an  express  money  order,  a  bank  check,  and  in  a  registered  letter.  Money 
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See  pages  30,  3J,  for  a  List  of  Contents  classified  according  to  subjects. 


LATEST  PUBLICATIONS. 


International  Text-Book  of  Sttrgfery.     See  page  32. 

American  Text-Book  of  Surgfery — Third  (Revised)  Edition.    See  page  5. 

American  Text-Book  of  Dis*  of  Eye,  Ear,  Nose,  and  Throat.    Page  3. 

American  Text-Book  of  Genito-Urinary  and  Skin  Diseases.    Page  4. 

Heisler^s  Embryologfy.     See  page  32. 

Nancrede^s  Principles  of  Surgery.     See  page  32. 

Jackson's  Diseases  of  the  Eye.    See  page  32. 

Kyle  on  the  Nose  and  Throat.     See  page  J5. 

Pryo/s  Pelvic  Inflammations.    See  pages  J9  and  32. 

Abbott's  Hygiene  of  Transmissible  Diseases.    See  page  32. 

Anders'  Practice  of  Medicine — Third  (Revised)  Edition.     See  page  6. 

Vierordt's  Medical  Diagfnosis — Fourth  (Revised)  Edition.    See  page  29. 

Church  and  Peterson's  Nervous  and  Mental  Diseases.     See  page  8. 

Da  Costa's  Surgery— Revised  and  Enlarged  Edition.     See  page  JO. 

Saunders'  Medical  Hand-Atlases.    See  page  2. 

Griffith  on  the  Baby — Revised  Edition.     See  page  12. 

Butler's  Materia  Medica  and  Therapeutics — Third  (Revised)  Ed.  Page  8. 

De  Schweinitz's  Diseases  of  the  Eye^-Third  (Revised)  Ed.    See  page  JO. 

Vecki's  Sexual  Impotence.     See  page  28. 

Stoney's  Materia  Medica  for  Nurses.    See  page  28. 

McFarland's  Pathogenic  Bacteria — Revised  Edition.    See  page  17. 

American  Pocket  Medical  Dictionary — Second  (Revised)  Ed.     Page  JO. 

Stengel's  Text-Book  of  Pathology.    Second  Edition.    See  page  26. 

Hirst's  Text-Book  of  Obstetrics.    See  page  J3. 


SAUNDERS^  MEDICAL  HAND-ATLASES, 


The  series  of  books  included  under  this  title  consists  of  authorized  translations  into 
English  of  the  world-famous  Lehmann  Medicinische  Handatlanten,  which  for  sci- 
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In  planning  this  series  ot  books  arrangements  were  made  with  representative  publishers 
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many, where  work  of  this  kind  has  been  brought  to  the  greatest  perfection.  The  expense  of 
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ers have  been  enabled  to  secure  for  these  atlases  the  best  artistic  and  professional 
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— German,  English,  French,  Italian,  Russian,  Spanish,  Danish,  Swedish,  and  Hungarian, 

In  view  of  the  striking  success  of  these  works,  Mr.  Saunders  has  contracted  with  the 
publisher  of  the  original  German  edition  for  one  hundred  thousand  copies  of  the  atlases. 
In'  consideration  of  this  enormous  undertaking,  the  publisher  has  been  enabled  to  prepare 
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Atlas  of  Internal  Medicine  and  Clinical  Diagnosis.  By  Dr.  Chr.  Jakob,  of  Erlangen.  Edited 
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Atlas  of  Diseases  of  the  Larynx.  By  Dr.  L.  GriJnwald,  of  Munich.  Edited  by  Charles  P. 
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Atlas  of  Orthopedic  Surgery.  Atlas  of  Psychiatry. 

Atlas  of  General  Surgery.  Atlas  of  Diseases  of  the  Ear. 


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Morocco,  $8.00  net.     So/d  by  Subscription. 
"This  volume  is  one  of  the  best  yet  issued  of  the  puhhsher's  series  of '  American  Text- 
Books.'     The  list  of  contributors  represents  an    extraordinary  array  of  talent  and  extended 
experience.     The  book  will  easily  take  the  place   in  comprehensiveness  and  value  of  the 
half  dozen  or  more  costly  works  on  these  subjects  which  have  heretofore  been  necessary  to 
a  well-equipped  library." — New  York  Polyclinic. 

AN  AMERICAN  TEXT=BOOK  OF  GYNECOLOGY,  MEDICAL  AND 
SURGICAL.     Second  Edition,  Revised. 

By  10  of  the  Leading  Gynecologists  of  America.  Edited  by  J-  M. 
Baldy,  M.  D.,  Professor  of  Gynecology  in  the  Philadelphia  Polyclinic, 
etc.  Handsome  imperial  octavo  volume  of  718  pages,  with  341  illus- 
trations in  the  text,  and  38  colored  and  half-tone  plates.  Cloth,  $6.00 
net;  Sheep  or  Half  Morocco,  $7.00  net.     Sold  by  Subscription. 

"  It  is  practical  from  beginning  to  end.  Its  descriptions  of  conditions,  its  recommen- 
dations for  treatment,  and  above  all  the  necessary  technique  of  different  operations,  are 
clearly  and  admirably  presented.  .  .  .  It  is  well  up  to  the  most  advanced  views  of  the 
day,  and  embodies  all  the  essential  points  of  advanced  American  gynecology.  It  is  destined 
to  make  and  hold  a  place  in  gynecological  literature  which  will  be  peculiarly  its  own." — 
Medical  Record,  New  York. 

AN  AMERICAN  TEXT=BOOK  OF  LEGAL  MEDICINE  AND  TOXI- 
COLOGY. 

Edited  by  Frederick  Peterson,  M.D.,  Clinical  Professor  of  Mental 
Diseases  in  the  Woman's  Medical  College,  New  York;  Chief  of  Clinic, 
Nervous  Department,  College  of  Physicians  and  Surgeons,  New  York ; 
and  Walter  S.  Haines,  M.D.,  Professor  of  Chemistry,  Pharmacy, 
and  Toxicology  in  Rush  Medical  College,  Chicago.     In  Preparation. 

AN  AMERICAN  TEXT=BOOK  OF  OBSTETRICS. 

By  15  Eminent  American  Obstetricians.  Edited  by  Richard  C.  Nor- 
Ris,  M.D.;  Art  Editor,  Robert  L.  Dickinson,  M.D.  One  handsome 
imperial  octavo  volume  of  1014  pages,  with  nearly  900  beautiful  colored 
and  half-tone  illustrations.  Cloth,  $7.00  net;  Sheep  or  Half  Morocco, 
^8.00  net.     Sold  by  Subscription. 

"  Permit  me  to  say  that  your  American  Text-Book  of  Obstetrics  is  the  most  magnificent 
medical  work  that  I  have  ever  seen.  I  congratulate  you  and  thank  you  for  this  superb  work, 
which  alone  is  sufficient  to  place  you  first  in  the  ranks  of  medical  publishers." — Alexander 
J.  C.  .Skenp:,  Professor  of  Gynecology  in  the  Long  Island  College  Hospital,  Brooklyn,  N.  Y. 

"  This  is  the  most  sumptuously  illustrated  work  on  midwifery  that  has  yet  appeared.  In 
the  number,  the  excellence,  and  the  beauty  of  production  of  the  illustrations  it  far  surpasses 
every  other  book  upon  the  subject.  This  feature  alone  makes  it  a  work  which  no  medical 
library  should  omit  to  purchase." — British  Medical  Journal. 

"  yVs  an  authority,  as  a  book  of  reference,  as  a  '  working  book  '  for  the  student  or  prac- 
titioner, we  commend  it  because  we  believe  there  is  no  better." — American  Journal  of  the 
Medical  Sciences. 

Illustrated  Catalogue  of  the  "American  Text-Books  "  sent  free  upon  application. 


Medical  Publications  of  W,  B,  Saunders.  5 

AN  AMERICAN  TEXT=BOOK  OF  PATHOLOGY. 

Edited  by  John  Guiteras,  M.D.,  Professor  of  General  Pathology  and 
of  Morbid  Anatomy  in  the  University  of  Pennsylvania ;  and  David 
RiESMAN,  M.D. ,  Demonstrator  of  Pathological  Histology  in  the 
University  of  Pennsylvania.     In  Preparation. 

AN  AMERICAN  TEXT=BOOK  OF  PHYSIOLOGY. 

By  I  o  of  the  Leading  Physiologists  of  America.  Edited  by  William 
H.  Howell,  Ph.D.,  M.D.,  Professor  of  Physiology  in  the  Johns  Hop- 
kins University,  Baltimore,  Md.  One  handsome  imperial  octavo 
volume  of  1052  pages.  Illustrated.  Cloth,  ^6.00  net;  Sheep  or  Half 
Morocco,  ^7.00  net.     Sold  by  Subscription. 

"  We  can  commend  it  most  heartily,  not  only  to  all  students  of  physiology,  but  to  every 
physician  and  pathologist,  as  a  valuable  and  comprehensive  work  of  reference,  written  by 
men  who  are  of  eminent  authority  in  their  own  special  subjects." — London  Lancet. 

"  To  the  practitioner  of  medicine  and  to  the  advanced  student  this  volume  constitutes, 
we  believe,  the  best  exposition  of  the  present  status  of  the  science  of  physiology  in  the 
English  language." — American  Jou7'nal  of  the  Medical  Sciences. 

AN   AMERICAN  TEXT=BOOK   OF   SURGERY.     Third  Edition. 

By  II  Eminent  Professors  of  Surgery.  Edited  by  William  W.  Keen, 
M.D.,  LL.D.,  and  J.  William  White,  M.D.,  Ph.D.  Handsome  im- 
perial octavo  volume  of  1230  pages,  with  496  wood-cuts  in  the  text, 
and  37  colored  and  half-tone  plates.  Thoroughly  revised  and  enlarged, 
with  a  section  devoted  to  "  The  Use  of  the  Rontgen  Rays  in  Surgery." 
Cloth,  ^7.00  net;  Sheep  or  Half  Morocco,  $8.00  net. 

*'  Personally,  I  should  not  mind  it  being  called  THE  Text-Book  (instead  of  A  Text- 
Book)  ,  for  I  know  of  no  single  volume  which  contains  so  readable  and  complete  an  account 
of  the  science  and  art  of  Surgery  as  this  does." — Edmund  Owen,  F.R.C.S.,  Member  of 
the  Board  of  Examiners  of  the  Royal  College  of  Surgeons,  England. 

"  If  this  text-book  is  a  fair  reflex  of  the  present  position  of  American  surgery,  we  must 
admit  it  is  of  a  very  high  order  of  merit,  and  that  English  surgeons  will  have  to  look  very 
carefully  to  their  laurels  if  they  are  to  preserve  a  position  in  the  van  of  surgical  practice." — 
London  Lancet. 

AN  AMERICAN  TEXT=BOOK  OF  THE  THEORY  AND  PRACTICE 
OF  MEDICINE. 

By  12  Distinguished  American  Practitioners.  Edited  by  William 
Pepper,  M.D.,  LL.D.,  Professor  of  the  Theory  and  Practice  of  Medi- 
cine and  of  Clinical  Medicine  in  the  University  of  Pennsylvania.  Two 
handsome  imperial  octavo  volumes  of  about  1000  pages  each.  Illus- 
trated. Prices  per  volume :  Cloth,  ^5.00  net ;  Sheep  or  Half  Morocco, 
^6.00  net.     Sold  by  Subscription. 

•'  I  am  quite  sure  it  will  commend  itself  both  to  practitioners  and  students  of  medicine, 
and  become  one  of  our  most  popular  text-books." — Alfred  Loomis,  M.D.,  LL.D,,  Pro- 
fessor of  Pathology  and  Practice  of  Medicine,  University  of  the  City  of  New  York. 

"  We  reviewed  the  first  volume  of  this  work,  and  said  :  '  It  is  undoubtedly  one  of  the 
best  text-books  on  the  practice  of  medicine  which  we  possess. '  A  consideration  of  the 
second  and  last  volume  leads  us  to  modify  that  verdict  and  to  say  that  the  completed  work 
is  in  our  opinion  the  best  of  its  kind  it  has  ever  been  our  fortune  to  see." — New  York  Medical 
Journal. 

.    Illustrated  Catalogue  of  the  ** American  Text-Books*'  sent  free  upon  application. 


6  Medical  Publications  of  W.  B.  Saunders. 

AN  AMERICAN  YEAR-BOOK  OF  MEDICINE  AND  SURGERY. 

A  Yearly  Digest  of  Scientific  Progress  and  Authoritative  Opinion  in  all 
branches  of  Medicine  and  Surgery,  drawn  from  journals,  monographs, 
and  text-books  of  the  leading  American  and  Foreign  authors  and 
investigators.  Collected  and  arranged,  with  critical  editorial  com- 
ments, by  eminent  American  specialists  and  teachers,  under  the  general 
editorial  charge  of  George  M.  Gould,  M.D.  One  handsome  imperial 
octavo  volume  of  about  1200  pages.  Uniform  in  style,  size,  and 
general  make-up  with  the  "American  Text-Book"  Series.  Cloth, 
^6.50  net ;  Half  Morocco,  ^7.50  net.     So/d  by  Subscription. 

"  It  is  difficult  to  know  which  to  admire  most — the  research  and  industry  of  the  distin- 
guished band  of  experts  whom  Dr.  Gould  has  enlisted  in  the  service  of  the  Year-Book,  or  the 
wealth  and  abundance  of  the  contributions  to  every  department  of  science  that  have  been 
deemed  worthy  of  analysis.  .  .  .  It  is  much  more  than  a  mere  compilation  of  abstracts, 
for,  as  each  section  is  entrusted  to  experienced  and  able  contributors,  the  reader  has  the 
advantage  of  certain  critical  commentaries  and  expositions  .  .  .  proceeding  from  writers 
fully  qualified  to  perform  these  tasks.  .  .  .  It  is  emphatically  a  boolc  which  should  find 
a  place  in  every  medical  library,  and  is  in  several  respects  more  useful  than  the  famous 
'  Jahrbiicher  '  of  Germany." — London  Lancet. 

THE  AMERICAN  POCKET  MEDICAL  DICTIONARY. 

[See  Dorland'''S  Pocket  Dictionary,  page  10.] 

ANDERS'  PRACTICE  OF  MEDICINE.  Third  Revised  Edition. 
A  Text-Boole  of  the  Practice  of  Medicine.  By  James  M.  Anders, 
M.D.,  Ph.D.,  LL.D.,  Professor  of  the  Practice  of  Medicine  and  of 
Clinical  Medicine,  Medico-Chirurgical  College,  Philadelphia.  In  one 
handsome  octavo  volume  of  1292  pages,  fully  illustrated.  Cloth, 
^5.50  net;  Sheep  or  Half  Morocco,  ^6.50  net. 

"  It  is  an  excellent  book, — concise,  comprehensive,  thorough,  and  up  to  date.  It  is  a 
credit  to  you  ;  but,  more  than  that,  it  is  a  credit  to  the  profession  of  Philadelphia — to  us." 
James  C.  Wilson,  Professor  of  the  Practice  of  Medicine  and  Clinical  Medicine,  Jefferson 
Medical  College,  Philadelphia. 

ASHTON'S  OBSTETRICS.     Fourth  Edition,  Revised. 

Essentials  of  Obstetrics.  By  W.  Easterly  Ashton,  M.D.,  Pro. 
fessor  of  Gynecology  in  the  Medico-Chirurgical  College,  Philadelphia. 
Crown  octavo,  252  pages;  75  illustrations.  Cloth,  ^i. 00;  interleaved 
for  notes,  ^1.25. 

[See  Saunders'  Question- Cotnpends,  page  21.] 

"  Embodies  the  whole  subject  in  a  nut-shell.  We  cordially  recommend  it  to  our  read- 
ers."— Chicago  Medical  Times. 

BALL'S  BACTERIOLOGY.     Third  Edition,  Revised. 

Essentials  of  Bacteriology  ;  a  Concise  and  Systematic  Introduction 
to  the  Study  of  Micro-organisms.  By  M.  V.  Ball,  M.D.,  Bacteriol- 
ogist to  St.  Agnes'  Hospital,' Philadelphia,  etc.  Crown  octavo,  218 
pages;  82  illustrations,  some  in  colors,  and  5  plates.  Cloth,  jgi.oo; 
interleaved  for  notes,  $1.25. 

[See  Samiders'  Question- Comfends,  page  21.] 

"  The  student  or  practitioner  can  readily  obtain  a  knowledge  of  the  subject  from  a  perusal 
of  this  book.     The  illustrations  are  clear  and  satisfactory." — Medical  Record,  New  York. 


Medical  Publications  of  W.  B.  Saunders.  7 

BASTIN'S  BOTANY. 

Laboratory  Exercises  in  Botany.  By  Edson  S.  Bastin,  M.A., 
late  Professor  of  Materia  Medica  and  Botany,  Philadelphia  College  of 
Pharmacy.    Octavo  volume  of  536  pages,  with  87  plates.    Cloth,  $2.50. 

"  It  is  unquestionably  the  best  text-book  on  the  subject  that  has  yet  appeared.  The 
work  is  eminently  a  practical  one.  We  regard  the  issuance  of  this  book  as  an  important 
event  in  the  history  of  pharmaceutical  teaching  in  this  country,  and  predict  for  it  an  unquali- 
fied success." — Alumni  Jieport  to  the  Philadelphia  College  of  Pharjnacy. 

' '  There  is  no  work  like  it  in  the  pharmaceutical  or  botanical  literature  of  this  country, 
and  we  predict  for  it  a  wide  circulation." — Americati  Jotimal  of  Pharmacy, 

BECK'S  SURGICAL  ASEPSIS. 

A  Manual  of  Surgical  Asepsis.  By  Carl  Beck,  M.D.,  Surgeon  to 
S,t.  Mark's  Hospital  and  the  New  York  German  Poliklinik,  etc.  306 
pages;   65  text-illustrations,  and  12  full-page  plates.     Cloth,  ^1.25  net. 

"An  excellent  exposition  of  the  'very  latest'  in  the  treatment  of  wounds  as  practised 
by  leading  German  and  American  surgeons." — Birminghatn  (Eng.)  Medical  Review. 

"  This  little  volume  can  be  recommended  to  any  who  are  desirous  of  learning  the  details 
of  asepsis  in  surgery,  for  it  will  serve  as  a  trustworthy  guide." — London  Lancet. 

BOISLINIERE'S  OBSTETRIC  ACCIDENTS,  EMERGENCIES,  AND 
OPERATIONS. 
Obstetric  Accidents,  Emergencies,  and  Operations.     By  L.  Ch. 

BoisLiNiERE,  M.D.,  late  Emeritus  Professor  of  Obstetrics,  St.  Louis 
Medical  College.    381  pages,  handsomely  illustrated.    Cloth,  ;^2.oo  net. 

"  It  is  clearly  and  concisely  written,  and  is  evidently  the  work  of  a  teacher  and  practi- 
tioner of  large  experience." — B^'itish  Medical fotirnal. 

"  A  manual  so  useful  to  the  student  or  the  general  practitioner  has  not  been  brought  to 
our  notice  in  a  long  time.  The  field  embraced  in  the  title  is  covered  in  a  terse,  interesting 
way." — Yale  Medical  Journal. 

BROCKWAY'S  MEDICAL  PHYSICS.     Second  Edition,  Revised. 
Essentials  of   Medical   Physics.     By  Fred  J.  Brockway,  M.D., 
Assistant  Demonstrator  of  Anatomy  in  the  College  of  Physicians  and 
Surgeons,  New  York.     Crown  octavo,  330  pages  ;   155  fine  illustrations. 
Cloth,  $1.00  net;  interleaved  for  notes,  ^1.25  net. 

[See  Saunders^  Qtcestion-Compends,  page  21.] 

"  The  student  who  is  well  versed  in  these  pages  will  certainly  prove  qualified  to  com« 
prebend  with  ease  and  pleasure  the  great  majority  of  questions  involving  physical  principles 
likely  to  be  met  with  in  his  medical  studies." — American  Practitioner  and  News. 

"We  know  of  no  manual  that  affords  the  medical  student  a  better  or  more  concise 
exposition  of  physics,  and  the  book  may  be  commended  as  a  most  satisfactory  presentation 
of  those  essentials  that  are  requisite  in  a  course  in  medicine." — Neiv  York  Medical  Jou7-nal, 

"  It  contains  all  that  one  need  know  on  the  subject,  is  well  written,  and  is  copiously 
illustrated." — Medical  Record,   New  York. 

BURR  ON  NERVOUS  DISEASES. 

A  Manual  of  Nervous  Diseases.  By  Charles  W.  Burr,  M.D., 
Clinical  Professor  of  Nervous  Diseases,  Medico-Chirurgical  College, 
Philadelphia ;  Pathologist  to  the  Orthopedic  Hospital  and  Infirmary 
for  Nervous  Diseases;  Visiting  Physician  to  St.  Joseph's  Hospital,  etc. 
In  PreparatAon. 


8  Medical  Publications  of  W.  B.  Saunders. 

BUTLER'S  MATERIA  MEDICA,  THERAPEUTICS,  AND  PHAR- 
MACOLOGY. Third  Edition,  Revised. 
A  Text=Book  of  Materia  Medica,  Therapeutics,  and  Pharma- 
cology. By  George  F.  Butler,  Ph.G.,  M.D.,  Professor  of  Materia 
Medica  and  of  Clinical  Medicine  in  the  College  of  Physicians  and 
Surgeons,  Chicago ;  Professor  of  Materia  Medica  and  Therapeutics, 
Northwestern  University,  Woman's  Medical  School,  etc.  Octavo,  874 
pages,  illustrated.     Cloth,  ^4.00  net;    Sheep,  ^5.00  net. 

"  Taken  as  a  whole,  the  book  may  fairly  be  considered  as  one  of  the  most  satisfactory 
of  any  single-volume  works  on  materia  medica  in  the  market,"— yozirnal  of  tAe  American 
Medical  Association. 

CERNA  ON  THE  NEWER  REMEDIES.  Second  Edition,  Revised. 
Notes  on  the  Newer  Remedies,  their  Therapeutic  Applications 
and  Modes  of  Administration.  By  David  Cerna,  M.D.,  Ph.D., 
formerly  Demonstrator  of  and  Lecturer  on  Experimental  Therapeutics 
in  the  University  of  Pennsylvania ;  Demonstrator  of  Physiology  in  the 
Medical  Department  of  the  University  of  Texas.  Rewritten  and 
greatly  enlarged.     Post-octavo,   253  pages.     Cloth,  ^1.25. 

"  The  appearance  of  this  new  edition  of  Dr.  Cerna's  very  valuable  work  shows  that  it 
is  properly  appreciated.  The  book  ought  to  be  in  the  possession  of  every  practising  physi- 
cian."— ISferu  York  Aledical  Journal. 

CHAPIN  ON  INSANITY. 

A  Compendium  of  Insanity.     By  John  B.  Chapin,  M.D.,  LL.D., 

Physician-in-Chief,  Pennsylvania  Hospital  for  the  Insane ;  late;  Physi- 
cian-Superintendent of  the  Willard  State  Hospital,  New  York ;  Hon- 
orary Member  of  the  Medico-Psychological  Society  of  Great  Britain, 
of  the  Society  of  Mental  Medicine  of  Belgium.  i2mo,  234  pages, 
illustrated.     Cloth,  ^1.25  net. 

"  The  practical  parts  of  Dr.  Chapin's  book  are  what  constitute  its  distinctive  merit.  We 
desire  especially  to  call  attention  to  the  fact  that  on  the  subject  of  therapeutics  of  insanity 
the  work  is  exceedingly  valuable.  It  is  not  a  made  book,  but  a  genuine  condensed  thesis, 
which  has  all  the  value  of  ripe  opinion  and  all  the  charm  of  a  vigorous  and  natural  style." — 
Philadelphia  Aledical  Jou7-nal. 

CHAPMAN'S  MEDICAL  JURISPRUDENCE  AND  TOXICOLOGY. 
Second  Edition,  Revised. 
Medical  Jurisprudence  and  Toxicology.  By  Henry  C.  Chapman, 
M.D.,  Professor  of  Institutes  of  Medicine  and  Medical  Jurisprudence 
in  the  Jefferson  Medical  College  of  Philadelphia.  254  pages,  with  55 
illustrations  and  3  full-page  plates  in  colors.     Cloth,  ^1.50  net. 

"The  best  book  of  its  class  for  the  undergraduate  that  we  know  of." — N'ezv  York 
Medical  Times. 

CHURCH  AND  PETERSON'S  NERVOUS  AND  MENTAL  DISEASES. 
Nervous  and  Mental  Diseases.  By  Archibald  Church,  M.  D., 
Professor  of  Mental  Di.seases  and  Medical  Jurisprudence  in  the  North- 
western University  Medical  School,  Chicago ;  and  Frederick  Peter- 
.son,  M.  D.,  Clinical  Professor  of  Mental  Diseases,  Woman's  Medical 
College,  N.  Y.;  Chief  of  Clinic,  Nervous  Dept.,  College  of  Physi- 
cians and  Surgeons,  N.  Y.  Handsome  octavo  volume  of  843  pages, 
profusely  illustrated.     Cloth,  $5.00  net;   Half  Morocco,  $6.00  net. 


Medical  Publications  of  W.  B.  Saunders.  9 

CLARKSON'S  HISTOLOGY. 

A  Text=Book    of    Histology,    Descriptive   and    Practical.      By 

Arthur  Clarkson,  M.B.,  CM.  Edin.,  formerly  Demonstrator  oif 
Physiology  in  the  Owen's  College,  Manchester;  late  Demonstrator  of 
Physiology  in  Yorkshire  College,  Leeds.  Large  octavo,  554  pages; 
22  engravings  in  the  text,  and  174  beautifully  colored  original  illustra- 
tions.     Cloth,  strongly  bound,  ^4.00  net. 

"  The  work  must  be  considered  a  valuable  addition  to  the  list  of  available  text- books, 
and  is  to  be  highly  recommended." — New  York  Medical  Journal. 

' '  This  is  one  of  the  best  works  for  students  we  have  ever  noticed.  We  predict  that  the 
book  will  attain  a  well-deserved  popularity  among  our  students." — Chicago  Medical  Recorder. 

CLIMATOLOGY. 

Transactions  of  the  Eighth  Annual  Meeting  of  the  American 
Climatological  Association,  held  in  Washington,  September  22-25, 
1891.  Forming  a  handsome  octavo  volume  of  276  pages,  uniform  with 
remainder  of  series.      (A  limited  quantity  only.)     Cloth,  ^1.50. 

COHEN  AND  ESHNER'S  DIAGNOSIS. 

Essentials  of  Diagnosis.  By  Solomon  Solis-Cohen,  M.D.,  Pro- 
fessor of  Clinical  Medicine  and  Applied  Therapeutics  in  the  Philadel- 
phia Polyclinic  ;  and  Augustus  A.  Eshner,  M.D.,  Professor  of  Clinical 
Medicine  in  the  Philadelphia  Polyclinic.  Post-octavo,  382  pages;  55 
illustrations.      Cloth,  ^1.50  net. 

[See  Saunders''  Question- Compends,  page  21.] 

"  We  can  heartily  commend  the  book  to  all  those  who  contemplate  purchasing  a  'com- 
pend.'  It  is  modern  and  complete,  and  will  give  more  satisfaction  than  many  other  works 
which  are  perhaps  too  prolix  as  well  as  behind  the  times." — Medical  Review,  St.  Louis. 

CORWIN'S  PHYSICAL  DIAGNOSIS.     Third  Edition,  Revised. 

Essentials  of  Physical  Diagnosis  of  the  Thorax.  By  Arthur 
M.  Corwin,  A.M.,  M.D.,  Demonstrator  of  Physical  Diagnosis  in  Rush 
Medical  College,  Chicago ;  Attending  Physician  to  Central  Free  Dis- 
pensary, Department  of  Rhinology,  Laryngology,  and  Diseases  of  the 
Chest,  Chicago.    219  pages,  illustrated.   Cloth,  flexible  covers,  ^1.25  net. 

"It  is  excellent.  The  student  who  shall  use  it  as  his  guide  to  the  careful  study  of 
physical  exploration  upon  normal  and  abnormal  subjects  can  scarcely  fail  to  acquire  a  good 
working  knowledge  of  the  subject." — Philadelphia  Polyclinic. 

"A  most  excellent  little  work.  It  brightens  the  memory  of  the  differential  diagnostic 
signs,  and  it  arranges  orderly  and  in  sequence  the  various  objective  phenomena  to  logical 
solution  of  a  careful  diagnosis." — Jotirnal  of  Nervous  and  Mental  Diseases. 

CRAGIN'S  GYNECOLOGY.     Fourth  Edition,  Revised. 

Essentials  of  Gynaecology.  By  Edwin  B.  Cragin,  M.  D.,  Lecturer 
in  Obstetrics,  College  of  Physicians  and  Surgeons,  New  York.  Crown 
octavo,  200  pages;  62  illustrations.     Cloth,  $1.00  ;  interleaved  for  notes, 

[See  Saunders'  Question- Compends,  page  21.] 

"  A  handy  volume,  and  a  distinct  improvement  on  students'  compends  in  general.  No 
author  who  was  not  himself  a  practical  gynecologist  could  have  consulted  the  student's  needs 
so  thoroughly  as  Dr.  Cragin  has  done." — Medical  Record,  New  York. 


10  Medical  Publications  of  W.  B.  Saunders. 

CROOKSHANK'S  BACTERIOLOGY.     Fourth  Edition,  Revised. 

A  Text=Book  of  Bacteriology.  By  Edgar  M.  Crookshank,  M.B., 
Professor  of  Comparative  Pathology  and  Bacteriology,  King's  College, 
London.  Octavo  volume  of  700  pages,  with  273  engravings  and  22 
original  colored  plates.     Cloth,  $6.50  net;  Half  Morocco,  ^7.50  net. 

"  To  the  student  who  wishes  to  obtain  a  good  resume  of  what  has  been  done  in  bacteri- 
ology, or  who  wishes  an  accurate  account  of  the  various  methods  of  research,  the  book  may 
be  recommended  with  confidence  that  he  will  find  there  what  he  requires." — Lo7idon  Lancet. 

Da  COSTA'S  SURGERY.  Second  Ed.,  Revised  and  Greatly  Enlarged. 
Modern  Surgery,  General  and  Operative.  By  John  Chalmers 
DaCosta,  M.D.,  Clinical  Professor  of  Surgery,  Jefferson  Medical 
College,  Philadelphia ;  Surgeon  to  the  Philadelphia  Hospital,  etc. 
Handsome  octavo  volume  of  900  pages,  profusely  illustrated.  Cloth, 
^4.00  net;  Half  Morocco,  1^5.00  net. 

"We  know  of  no  small  work  on  surgery  in  the  English  language  which  so  well  fulfils 
the  requirements  of  the  modern  student." — Medico-Chirurgical Journal,  Bristol,  England. 

DE  SCHWEINITZ  ON  DISEASES  OF  THE  EYE.      Third  Edition, 
Revised. 
Diseases  of   the  Eye.     A  Handbook   of   Ophthalmic   Practice. 

By  G.  E.  DE  ScHWEiNiTZ,  M.D.,  Professor  of  Ophthalmology  in  the 
Jefferson  Medical  College,  Philadelphia,  etc.  Handsome  royal  octavo 
volume  of  696  pages,  with  256  fine  illustrations  and  2  chromo-litho- 
graphic  plates.     Cloth,  ^4.00  net ;  Sheep  or  Half  Morocco,  ^5.00  net. 

"  A  clearly  written,  comprehensive  manual.  One  which  we  can  commend  to  students 
as  a  reliable  text-book,  written  with  an  evident  knowledge  of  the  wants  of  those  entering 
upon  the  study  of  this  special  branch  of  medical  science." — British  Medical  Journal. 

"  A  work  that  will  meet  the  requirements  not  only  of  the  specialist,  but  of  the  general 
practitioner  in  a  rare  degree.  I  am  satisfied  that  unusual  success  awaits  it." — WiLLlAM 
Pepper,  M.D.,  Projessor  of  the  Theory  atid  Practice  of  Medicine  and  Clinical  Medicine, 
University  of  Pennsylvania. 

DORLAND'S  DICTIONARY.     Second  Edition,  Revised. 

The  American  Pocket  Medical  Dictionary.  Containing  the  Pro- 
nunciation and  Definition  of  all  the  principal  words  and  phrases,  and  a 
large  number  of  useful  tables.  Edited  by  W.  A.  Newman  Borland, 
M.  D.,  Assistant  Demonstrator  of  Obstetrics,  University  of  Pennsylvania; 
Fellow  of  the  American  Academy  of  Medicine.  518  pages  ;  handsomely 
bound  in  full  leather,  limp,  with  gilt  edges  and  patent  index.  Price, 
^i.oo  net;  with  thumb  index,  $1.25  net. 

DORLAND'S  OBSTETRICS. 

A  Manual  of  Obstetrics.  By  W.  A.  Newman  Dorland,  M.D., 
Assistant  Demonstrator  of  Obstetrics,  University  of  Pennsylvania; 
Instructor  in  Gynecology  in  the  Philadelphia  Polyclinic.  760  pages; 
163  illustrations  in  the  text,  and  6  full-page  plates.     Cloth,  $2.50  net. 

"  By  far  the  best  book  on  this  subject  that  has  ever  come  to  our  notice." — American 
Medical  Review. 

"  It  has  rarely  lieen  our  duty  to  review  a  book  which  has  given  us  more  pleasure  in  its 
perusal  and  more  satisfaction  in  its  criticism.  It  is  a  veritable  encyclopedia  of  knowledge, 
a  gold  mine  of  practical,  concise  thoughts." — American  Medico-Surgical  Bulletin. 


Medical  Publications  of  W.  B.  Saunders.  11 

FROTHINQHAM'S  GUIDE  FOR  THE  BACTERIOLOGIST. 

Laboratory  Guide  for  the  Bacteriologist.  By  Langdon  Froth- 
INGHAM,  M.D.V.,  Assistant  in  Bacteriology  and  Veterinary  Science, 
Sheffield  Scientific  School,  Yale  University.    Illustrated.    Cloth,  75  cts. 

"  It  is  a  convenient  and  useful  little  work,  and  will  more  than  repay  the  outlay  neces- 
sary for  its  purchase  in  the  saving  of  time  which  would  otherwise  be  consumed  in  looking 
up  the  various  points  of  technique  so  clearly  and  concisely  laid  down  in  its  pages." — Ameri- 
can Medico- Surgical  Bulletin. 

GARRIGUES'  DISEASES  OF  WOMEN.  Second  Edition,  Revised. 
Diseases  of  Women.  By  Henry  J.  Garrigues,  A.M.,  M.D.,  Pro- 
fessor of  Gynecology  in  the  New  York  School  of  Clinical  Medicine ; 
Gynecologist  to  St.  Mark's  Hospital  and  to  the  German  Dispensary, 
New  York  City,  etc.  Handsome  octavo  volume  of  728  pages,  illus- 
trated by  335  engravings  and  colored  plates.  Cloth,  $4.00  net; 
Sheep  or  Half  Morocco,  $5.00  net. 

"  One  of  the  best  text-books  for  students  and  practitioners  which  has  been  published  in 
the  English  language  ;  it  is  condensed,  clear,  and  comprehensive.  The  profound  learning 
and  great  clinical  experience  of  the  distinguished  author  find  expression  in  this  book  in  a 
most  attractive  and  instructive  form.  Young  practitioners  to  whom  experienced  consultants 
may  not  be  available  will  find  in  this  book  invaluable  counsel  and  help." — Thad.  A. 
Reamy,  M.D.,  LL.D.,  Professor  of  Clinical  Gynecology,  Medical  College  of  Ohio. 

QLEASON'S  DISEASES  OF  THE  EAR.  Second  Edition,  Revised. 
Essentials  of  Diseases  of  the  Ear.  By  E.  B.  Gleason,  S.B., 
M.D.,  Clinical  Professor  of  Otology,  Medico-Chirurgical  College, 
Philadelphia ;  Surgeon-in-Charge  of  the  Nose,  Throat,  and  Ear  Depart- 
ment of  the  Northern  Dispensary,  Philadelphia.  208  pages,  with 
1 14  illustrations.  Cloth,  ^i. 00;  interleaved  for  notes,  1 1.25. 
[See  Saunders'  Question- Compends,  page  21.] 

"  It  is  just  the  book  to  put  into  the  hands  of  a  student,  and  cannot  fail  to  give  him  a 
useful  introduction  to  ear-affections  ;  while  the  style  of  question  and  answer  which  is  adopted 
throughout  the  book  is,  we  believe,  the  best  method  of  impressing  facts  permanently  on  the 
mind. " — Liverpool  Medico-  Chirurgical  fournal. 

GOULD  AND  PYLE'S  CURIOSITIES  OF  MEDICINE. 

Anomalies  and  Curiosities  of  Medicine.  By  George  M.  Gould, 
M.D.,  and  Walter  L.  Pyle,  M.D.  An  encyclopedic  collection  of 
rare  and  extraordinary  cases  and  of  the  most  striking  instances  of 
abnormality  in  all  branches  of  Medicine  and  Surgery,  derived  from  an 
exhaustive  research  of  medical  literature  from  its  origin  to  the  present 
day,  abstracted,  classified,  annotated,  and  indexed.  Handsome  im- 
perial octavo  volume  of  968  pages,  with  295  engravings  in  the  text, 
and  12  full-page  plates.  Cloth,  $6.00  net;  Half  Morocco,  ^7.00  net. 
Sold  by  Subscription. 

"  One  of  the  most  valuable  contributions  ever  made  to  medical  literature.  It  is,  so  far 
as  we  know,  absolutely  unique,  and  every  page  is  as  fascinating  as  a  novel.  Not  alone  for 
the  medical  profession  has  this  volume  value:  it  will  serve  as  a  book  of  reference  for  all  who 
are  interested  in  general  scientific,  sociologic,  or  medico-legal  topics." — Brooklyn  Medical 
Jou7'nal. 

"This  is  certainly  a  most  remarkable  and  interesting  volume.  It  stands  alone  among 
medical  literature,  an  anomaly  on  anomalies,  in  that  there  is  nothing  like  it  elsewhere  in 
medical  literature.  It  is  a  book  full  of  revelations  from  its  first  to  its  last  page,  and  cannot 
but  interest  and  sometimes  almost  horrify  its  readers." — American  Medico- Surgical  Bulletin. 


12  Medical  Publications  of  W.  B.  Saunders. 

GRAFSTROM'S    MECHANO=THERAPY. 

A  Text=Book  of  Mechano=Therapy  (^Massage  and  Medical  Qym= 
nasties).  By  Axel  V.  Grafstrom,  B.  Sc,  M.  D.,  late  Lieutenant  in 
the  Royal  Swedish  Army ;  late  House  Physician  City  Hospital,  Black- 
well's  Island,  New  York.    i2mo,  139  pages,  illustrated.   Cloth,  ^i. 00  net. 

GRIFFITH  ON  THE  BABY.     Second  Edition,  Revised. 

The  Care  of  the  Baby.  By  J.  P.  Crozer  Griffith,  M.D.,  Clini- 
cal Professor  of  Diseases  of  Children,  University  of  Pennsylvania; 
Physician  to  the  Children's  Hospital,  Philadelphia,  etc.  121110,  404 
pages,  with  67  illustrations  in  the  text,  and  5  plates.      Cloth,  ^1.50. 

"  The  best  book  for  the  use  of  the  young  mother  with  which  we  are  acquainted.  .  .  . 
There  are  very  few  general  practitioners  who  could  not  read  the  book  through  with  advan- 
tage. ' ' — Archives  of  Pediatrics. 

"The  whole  book  is  characterized  by  rare  good  sense,  and  is  evidently  written  by  a 
master  hand.  It  can  be  read  with  benefit  not  only  by  mothers  but  by  medical  students  and 
by  any  practitioners  who  have  not  had  large  opportunities  for  observing  children." — Ameri- 
can Jonr?ial  of  Obstetrics. 

GRIFFITH'S  WEIGHT  CHART. 

Infant's  Weight  Chart.  Designed  by  J.  P.  Crozer  Griffith,  M.D., 
Clinical  Professor  of  Diseases  of  Children  in  the  University  of  Penn- 
sylvania, etc.      25  charts  in  each  pad.      Per  pad,  50  cents  net. 

A  convenient  blank  for  keeping  a  record  of  the  child's  weight  during  the  first  two  years 
of  life.  Printed  on  each  chait  is  a  curve  representing  the  average  weight  of  a  healthy  infant, 
so  that  any  deviation  from  the  normal  can  readily  be  detected. 

GROSS,  SAMUEL  D.,  AUTOBIOGRAPHY  OF. 

Autobiography  of  Samuel  D.  Gross,  M.D.,  Emeritus  Professor  of 
Surgery  in  the  Jefferson  Medical  College,  Philadelphia,  with  Remi- 
niscences of  His  Times  and  Contemporaries.  Edited  by  his  Sons, 
Samuel  W.  Gross,  M.D.,  LL.D.,  late  Professor  of  Principles  of  Sur- 
gery and  of  Clinical  Surgery  in  the  Jefferson  Medical  College,  and 
A.  Haller  Gross,  A.M.,  of  the  Philadelphia  Bar.  Preceded  by  a 
Memoir  of  Dr.  Gross,  by  the  late  Austin  Flint,  M.D.,  LL.D.  In 
two  handsome  volumes,  each  containing  over  400  pages,  demy  octavo, 
extra  cloth,  gilt  tops,  with  fine  Frontispiece  engraved  on  steel.  Price 
per  volume,  $2.50  net. 

'•  Dr.  Gross  was  perhaps  the  most  eminent  exponent  of  medical  science  that  America 
has  yet  produced.  His  Autobiography,  related  as  it  is  with  a  fulness  and  completeness 
seldom  to  be  found  in  such  works,  is  an  interesting  and  valuable  book.  He  comments  on 
many  things,  especially,  of  course,  on  medical  men  and  medical  practice,  in  a  very  interest- 
ing way." — The  Spectator,  London,  England. 

HAMPTON'S  NURSING.  Second  Edition,  Revised  and  Enlarged. 
Nursing:  Its  Principles  and  Practice.  By  Isabel  Adams  Hamp- 
ton, Graduate  of  the  New  York  Training  School  for  Nurses  attached 
to  Bellevue  Hospital ;  late  Superintendent  of  Nurses  and  Principal  of 
the  Training  School  for  Nurses,  Johns  Hopkins  Hospital,  Baltimore, 
Md.    12  mo,  512  pages,  illustrated.     Cloth,  $2.00  net. 

"  Seldom  have  we  perused  a  book  upon  the  subject  that  has  given  us  so  mucli  jileasure 
as  the  one  before  us.  We  would  strongly  urge  upon  the  members  of  our  own  profession  the 
need  of  a  book  like  (his,  for  it  will  enable  each  of  us  to  become  a  training  school  in  him- 
self."—  Ontario  Medical  Journal. 


Medical  Publications  of  W,  B.  Saunders.  13 

HARE'S  PHYSIOLOGY.  Fourth  Edition,  Revised. 

Essentials  of  Piiysiology.  By  H.  A.  Hare,  M.D.,  Professor  of 
Therapeutics  and  Materia  Medica  in  the  Jefferson  Medical  College  of 
Philadelphia.  Crown  octavo,  239  pages.  Cloth,  ^i.oo  net;  inter- 
leaved for  notes,  I1.25  net. 

[See  Saunders^  Question- Compends,  page  21.] 

"The  best  condensation  of  physiological  knowledge  we  have  yet  seen." — Medical 
Record,  New  York. 

HART'S  DIET  IN  SICKNESS  AND  IN  HEALTH. 

Diet  in  Sickness  and  in  Health.  By  Mrs.  Ernest  Hart,  formerly 
Student  of  the  Faculty  of  Medicine  of  Paris  and  of  the  London  School 
of  Medicine  for  Women ;  with  an  Introduction  by  Sir  Henry 
Thompson,  F.R.C.S.,  M.D.,  London.     220  pages.      Cloth,  ^1.50. 

"  We  recommend  it  cordially  to  the  attention  of  all  practitioners ;  both  to  them  and  to 
their  patients  it  may  be  of  the  greatest  service." — New  York  Medical  Journal. 

HAYNES'  ANATOMY. 

A  Manual  of  Anatomy.  By  Irving  S.  Haynes,  M.D.,  Adjunct 
Professor  of  Anatomy  and  Demonstrator  of  Anatomy,  Medical  Depart- 
ment of  the  New  York  University,  etc.  680  pages,  illustrated  with  42 
diagrams  in  the  text,  and  134  full-page  half-tone  illustrations  from 
original  photographs  of  the  author's  dissections.      Cloth,  ^2.50  net. 

"  This  book  is  the  work  of  a  practical  instructor — one  who  knows  by  experience  the 
requirements  of  the  average  student,  and  is  able  to  meet  these  requirements  in  a  very  satis- 
factory way.      The  book  is  one  that  can  be  commended." — Medical  Record,  New  York. 

HEISLER'S  EMBRYOLOGY. 

A  Text=Book  of  Embryology.  By  John  C.  Heisler,  M.D.,  Pro- 
fessor of  Anatomy  in  the  Medico- Chirurgical  College,  Philadelphia.  Oc- 
tavo volume  of  405  pages,  handsomely  illustrated.    Cloth,  ^2.50  net. 

HIRST'S  OBSTETRICS. 

A  Text=Book  of  Obstetrics.  By  Barton  Cooke  Hirst,  M.  D., 
Professor  of  Obstetrics  in  the  University  of  Pennsylvania.  Handsome 
octavo  volume  of  848  pages,  with  618  illustrations,  and  7  colored 
plates.     Cloth,  ^5.00  net;   Sheep  or  Half  Morocco,  ^6.00  net. 

"  The  illustrations  are  numerous  and  are  works  of  art,  many  of  them  appearing  for  the 
first  time.  The  arrangerhent  of  the  subject-matter,  the  foot-notes,  and  index  are  beyond 
criticism.  As  a  true  model  of  what  a  modern  text-book  on  obstetrics  should  be,  we  feel 
justified  in  affirming  that  Dr.  Hirst's  book  is  without  a  rival." — New  York  Medical  Record. 

HYDE  AND  MONTGOMERY  ON  SYPHILIS  AND  THE  VENEREAL 
DISEASES. 
Syphilis  and  the  Venereal  Diseases.  By  James  Nevins  Hyde, 
M.D.,  Professor  of  Skin  and  Venereal  Diseases,  and  Frank  H.  Mont- 
gomery, M.D.,  Lecturer  on  Dermatology  and  Genito-Urinary  Diseases 
in  Rush  Medical  College,  Chicago,  111.  618  pages,  profusely  illustrated. 
Cloth,  $2.50  net. 

"  We  can  commend  this  manual  to  the  student  as  a  help  to  him  in  his  study  of  venereal 
diseases. ' ' — Liverpool  Medico-  Chirurgical  Journal. 

"The  best  student's  manual  which  has  appeared  on  the  subject." — St.  Louis  Medical 
and  Surgical  Journal. 


14  Medical  Publications  of  W.  B.  Saunders. 

JACKSON  AND  GLEASON'S  DISEASES  OF  THE  EYE,  NOSE,  AND 
THROAT.  Second  Edition,  Revised. 
Essentials  of  Refraction  and  Diseases  of  the  Eye.  By  Edward 
Jackson,  A.M.,  M.D.,  Professor  of  Diseases  of  the  Eye  in  the  Phila- 
delphia Polyclinic  and  College  for  Graduates  in  Medicine  ;  and — 
Essentials  of  Diseases  of  the  Nose  and  Throat.  By  E.  Bald- 
win Gleason,  M.D.,  Surgeon-in-Charge  of  the  Nose,  Throat,  and 
Ear  Department  of  the  Northern  Dispensary  of  Philadelphia.  Two 
volumes  in  one.  Crown  octavo,  290  pages;  124  illustrations.  Cloth, 
1 1. 00;  interleaved  for  notes,  ^1.25. 

[See  Saunders'  Question- Cojnpends,  page  21.] 

"  Of  great  value  to  the  beginner  in  these  branches.  The  authors  are  both  capable  men, 
and  know  what  a  student  most  needs." — Medical  Record,  New  York. 

KEATINQ'S  DICTIONARY.     Second  Edition,  Revised. 

A  New  Pronouncing  Dictionary  of  Medicine,  with  Phonetic 
Pronunciation,  Accentuation,  Etymology,  etc.  By  John  M. 
Keating,  M.D.,  LL.D.,  Fellow  of  the  College  of  Physicians  of  Phila- 
delphia ;  Vice-President  of  the  American  Paediatric  Society ;  Editor 
"Cyclopaedia  of  the  Diseases  of  Children,"  etc.;  and  Henry 
Hamilton,  Author  of  "A  New  Translation  of  Virgil's  yEneid  into 
English  Rhyme,"  etc.;  with  the  collaboration  of  J.  Chalmers  Da- 
Costa,  M.D.,  and  Frederick  A.  Packard,  M.D.  With  an  Appendix 
containing  Tables  of  Bacilli,  Micrococci,  Leucomaines,  Ptomaines; 
Drugs  and  Materials  used  in  Antiseptic  Surgery ;  Poisons  and  their 
Antidotes ;  Weights  and  Measures ;  Thermometric  Scales ;  New 
Official  and  Unofficial  Drugs,  etc.  One  volume  of  over  800  pages. 
Prices,  with  Denisori's  Patent  Ready-Reference  Index:  Cloth,  ^5.00 
net;  Sheep  or  Half  Morocco,  ^6.00  net;  Half  Russia,  ^6.50  net. 
Without  Patent  Index:  Cloth,  ^4.00  net;  Sheep  or  Half  Morocco, 
$5.00  net. 

"  I  am  much  pleased  with  Keating's  Dictionary,  and  shall  take  pleasure  in  recommend- 
ing it  to  my  classes." — Henry  M.  Lyman,  M.D.,  Professor  of  the  Principles  and  Practice 
of  Medicine,  Rusk  Medical  College,  Chicago,  III. 

"  I  am  convinced  that  it  will  be  a  very  valuable  adjunct  to  my  study-table,  convenient 
in  size  and  sufficiently  full  for  ordinary  use." — C.  A.  Lindsley,  M.D.,  Professor  of  the 
Theory  and  Practice  of  Aledicine,  Medical  Dept.    Yale  University. 

KEATINQ'S    LIFE   INSURANCE. 

How  to  Examine  for  Life  Insurance.  By  John  M.  Keating, 
M.  D.,  Fellow  of  the  College  of  Physicians  of  Philadelphia;  Vice- 
President  of  the  American  Paediatric  Society;  Ex- President  of  the 
Association  of  Life  Insurance  Medical  Directors.  Royal  octavo,  211 
pages  ;  with  two  large  half-tone  illustrations,  and  a  plate  prepared  by 
Dr.  McClellan  from  special  dissections ;  also,  numerous  other  illustra- 
tions.    Cloth,  $2.00  net. 

"  This  is  by  far  the  most  useful  book  which  has  yet  appeared  on  insurance  examination, 
a  subject  of  growing  interest  and  importance.  Not  the  least  valuable  portion  of  the  volume 
is  Part  II.,  which  consists  of  instructions  issued  to  their  examining  physicians  by  twenty-four 
representative  companies  of  this  country.  If  for  these  alone,  the  book  should  be  at  the  right 
hand  of  every  physician  interested  in  this  special  branch  of  medical  science." — The  Medical 
News. 


Medical  Pablications  of  W.  B.  Saunders.  15 


KEEN  ON  THE  SURGERY  OF  TYPHOID  FEVER. 

The   Surgical   Complications  and   Sequels  of   Typhoid    Fever. 

By  Wm.  W.  Keen,  M.D.,  LL.D.,  Professor  of  the  Principles  of  Sur- 
gery and  of  Clinical  Surgery,  Jefferson  Medical  College,  Philadelphia; 
Corresponding  Member  of  the  Societe  de  Chirurgie,  Paris ;  Honorary 
Member  of  the  Societe  Beige  de  Chirurgie,  etc.  Octavo  volume  of 
386  pages,  illustrated.     Cloth,  $3.00  net. 

"  This  is  probably  the  first  and  only  work  in  the  English  language  that  gives  the  reader 
a  clear  view  of  what  typhoid  fever  really  is,  and  what  it  does  and  can  do  to  the  human 
organism.  This  book  should  be  in  the  possession  of  every  medical  man  in  America." — 
American  Medico-Surgical  Bulletin. 

KEEN'S  OPERATION  BLANK.  Second  Edition,  Revised  Form. 
An  Operation  Blank,  with  Lists  of  Instruments,  etc.  Required 
in  Various  Operations.  Prepared  by  W.  W.  Keen,  M.D.,  LL.D., 
Professor  of  the  Principles  of  Surgery  in  Jefferson  Medical  College, 
Philadelphia.  Price  per  pad,  containing  blanks  for  fifty  operations, 
50  cents  net. 

KYLE  ON  THE  NOSE  AND  THROAT. 

Diseases  of  the  Nose  and  Throat.  By  D.  Braden  Kyle,  M.D., 
Clinical  Professor  of  Laryngology  and  Rhinology,  Jefferson  Medical 
College,  Philadelphia ;  Consulting  Laryngologist,  Rhinologist,  and 
Otologist,  St.  Agnes'  Hospital.  Handsome  octavo  volume  of  about 
630  pages,  with  over  150  illustrations  and  6  lithographic  plates.  Price, 
Cloth;  ^4.00  net ;   Half  Morocco,  ^5.00  net. 

LAINE'S  TEMPERATURE  CHART. 

Temperature  Chart.  Prepared  by  D.  T.  Laine,  M.D.  Size  8  x  13;^ 
inches.  A  conveniently  arranged  Chart  for  recording  Temperature, 
with  columns  for  daily  amounts  of  Urinary  and  Fecal  Excretions, 
Food,  Remarks,  etc.  On  the  back  of  each  chart  is  given  in  full  the 
method  of  Brand  in  the  treatment  of  Typhoid  Fever.  Price,  per  pad 
of  25  charts,  50  cents  net. 

"  To  the  busy  practitioner  this  chart  will  be  found  of  great  value  in  fever  cases,  and 
especially  for  cases  of  typhoid." — Indian  Lancet,  Calcutta. 

LOCKWOOD'S  practice  of  MEDICINE. 

A  Manual  of  the  Practice  of  Medicine.  By  George  Roe  Lock- 
wood,  M.D.,  Professor  of  Practice  in  the  Woman's  Medical  College 
of  the  New  York  Infirmary,  etc.  935  pages,  with  75  illustrations  in 
the  text,  and  22  full-page  plates.     Cloth,  ^2.50  net. 

"  Gives  in  a  most  concise  manner  the  points  essential  to  treatment  usually  enumerated 
in  the  most  elaborate  works." — Massachusetts  Medical  Journal. 

LONG'S  SYLLABUS  OF  GYNECOLOGY. 

A  Syllabus  of  Gynecology,  arranged  in  Conformity  with  "  An 
American  Text=Book  of  Gynecology."  By  J.  W.  Long,  M.D., 
Professor  of  Diseases  of  Women  and  Children,  Medical  College  of 
Virginia,  etc.      Cloth,  interleaved,  $1.00  net. 

"  The  book  is  certainly  an  admirable  resume  of  what  every  gynecological  student  and 
practitioner  should  know,  and  will  prove  of  value  not  only  to  those  who  have  the  '  American 
Text-Book  of  Gynecology,'  but  to  others  as  well." — Brooklyn  Medical  Journal, 


16  Medical  Publications  of  W.  B.  Saunders. 

MACDONALD'S  SURGICAL  DIAGNOSIS   \ND  TREATMENT. 

Surgical  Diagnosis  and  Treatment.  By  J.  W.  Macdonald,  M.D. 
Edin.,  F.R.  C.S.,  Edin.,  Professor  of  the  Practice  of  Surgery  and  of 
Clinical  Surgery  in  Hamline  University ;  Visiting  Surgeon  to  St. 
Barnabas'  Hospital,  Minneapolis,  etc.  Handsome  octavo  volume  of 
800  pages,  profusely  illustrated.  Cloth,  $5.00  net;  Half  Morocco, 
|6.oo  net. 

"  A  thorough  and  complete  work  on  surgical  diagnosis  and  treatment,  free  from  pad- 
ding, full  of  valuable  material,  and  in  accord  with  the  surgical  teaching  of  the  day." — T/te 
Medical  News,  New  York. 

"  The  work  is  brimful  of  just  the  kind  of  -jractical  information  that  is  useful  alike  to 
students  and  practitioners.  It  is  a  pleasure  to  commend  the  bock  because  of  its  intrinsic 
value  to  the  medical  practitioner." — Cincimiafi  Laticet- Clinic 

MALLORY  AND  WRIGHT'S  PATHOLOGICAL  TECHNIQUE. 

Pathological  Technique.  A  Practical  Manual  for  Laboratory  Work 
in  Pathology,  Bacteriology,  and  JMorbid  Anatomy,  with  chapters  on 
Post-Mortem  Technique  and  the  Performance  of  Autopsies.  By  Frank 
B.  ]SLa.llory,  A.]\L,  M.D.,  Assistant  Professor  of  Patholof}^  Harvarn 
University  Medical  School,  Boston;  and  James  H.  Wright,  A.M., 
M.D.,  Instructor  in  Pathology,  Harvard  University  jSIedical  School, 
Boston.  Octavo  volume  of  396  pages,  handsomely  illustrated.  Cloth, 
$2.50  net. 

"  I  have  been  looking  forward  to  the  publication  of  this  book,  and  I  am  glad  to  say  that 
I  find  it  to  be  a  most  useful  laboratory  and  post-mortem  guide,  full  of  practical  information, 
and  well  up  to  date." — William  H.  Welch,  Professor  of  Pathology,  Johns  Hopkins  Uni- 
versity, Baltimore,  Md. 

MARTIN'S   MINOR    SURGERY,   BANDAGING,    AND    VENEREAL 

DISEASES.  Second  Edition,  Revised. 
Essentials  of  Minor  Surgery,  Bandaging,  and  Venereal 
Diseases.  By  Edward  Martin,  A.M.,  M.D.,  Clinical  Professor  of 
Genito-Urinary  Diseases,  University  of  Pennsylvania,  etc.  Crown 
octavo,  166  pages,  with  78  illustrations.  Cloth,  $1.00;  interleaved  for 
notes,  §1.25. 

[See  Saunders'   Question- Compends,  page   21.] 

"A  very  practical  and  systematic  study  of  the  subjects,  and  shows  the  author's  famil- 
iarity with  the  needs  of  students." — Therapeutic  Gazette. 

MARTIN'S  SURGERY.     Sixth  Edition,  Revised. 

Essentials  of  Surgery.  Containing  also  Venereal  Diseases,  Surgi- 
cal Landmarks,  Minor  and  Operative  Surgery,  and  a  complete  de- 
scription, with  illustrations,  of  the  Handkerchief  and  Roller  Bandages. 
By  Edward  Martin,  A.M.,  M.D.,  Clinical  Professor  of  Genito- 
Urinary  Diseases,  University  of  Pennsylvania,  etc.  Crown  octavo,  338 
pages,  illustrated.  With  an  Appendix  containing  full  directions  for  the 
preparation  of  the  materials  used  in  Antiseptic  Surgery,  etc.  Cloth, 
$1.00;   interleaved  for  notes,  $1.25. 

[See  Saunders'  Question- Compends,  page  21.] 

"  Contains  all  necessary  essentials  of  modem  surgery  in  a  comparatively  small  space. 
Its  style  is  interesting,  and  its  illustrations  are  admirable." — Medical  and  Surgical  Reporter. 


Medical  Publications  of  W.  B.  Saunders.  17 

McFARLAND'S  PATHOGENIC  BACTERIA.  Second  Edition,  Re= 
vised  and  Greatly  Enlarged. 
Text=Book  upon  the  Pathogenic  Bacteria.  By  Joseph  McFar- 
LAND,  M.  D.,  Professor  of  Pathology  and  Bacteriology  in  the  Medico- 
Chirurgical  College  of  Philadelphia,  etc.  Octavo  volume  of  497  pages, 
finely  illustrated.     Cloth,  $2.50  net. 

"  Dr.  McFarland  has  treated  the  subject  in  a  systematic  manner,  and  has  succeeded  in 
presenting  in  a  concise  and  readable  form  the  essentials  of  bacteriology  up  to  date.  Alto- 
gether, the  book  is  a  satisfactory  one,  and  I  shall  take  pleasure  in  recommending  it  to  the 
students  of  Trinity  College." — H.  B.  Anderson,  M.D.  ,  Professor  of  Pathology  and  Bac- 
teriology, Trinity  Medical  College,  Toronto. 

MEIGS  ON  FEEDING  IN  INFANCY. 

Feeding  in  Early  Infancy.  By  Arthur  V.  Meigs,  M.D.  Bound 
in  limp  cloth,  flush  edges,  25  cents  net. 

"This  pamphlet  is  worth  many  times  over  its  price  to  the  physician.  The  author's 
experimenis  and  conclusions  are  original,  and  have  been  the  means  of  doing  much  good." — 
Medical  Bulletin. 

MOORE'S  ORTHOPEDIC  SURGERY. 

A  Manual  of  Orthopedic  Surgery.  By  James  E.  Moore,  M.D., 
Professor  of  Orthopedics  and  Adjunct  Professor  of  Clinical  Surgery, 
University  of  Minnesota,  College  of  Medicine  and  Surgery.  Octavo 
volume  of  356  pages,  handsomely  illustrated.      Cloth,  ^2.50  net. 

"  A  most  attractive  work.  The  illustrations  and  the  care  with  which  the  book  is  adapted 
to  the  wants  of  the  general  practitioner  and  the  student  are  worthy  of  great  praise." — Chicago 
Medical  Recorder. 

"A  very  demonstrative  work,  every  illustration  of  which  conveys  a  lesson.  The  work  is 
a  most  excellent  and  commendable  one,  which  we  can  certainly  endorse  with  pleasure." — 
St.  Louis  Medical  and  Surgical  Journal. 

MORRIS'S  MATERIA  MEDICA  AND  THERAPEUTICS.  Fifth 
Edition,  Revised. 
Essentials  of  Materia  Medica,  Therapeutics,  and  Prescription= 
Writing.  By  Henry  Morris,  M.D.,  late  Demonstrator  of  Thera- 
peutics, Jefferson  Medical  College,  Philadelphia ;  Fellow  of  the  College 
of  Physicians,  Philadelphia,  etc.  Crown  octavo,  288  pages.  Cloth, 
^i.oo;  interleaved  for  notes,  $1.25. 

[See  Saunders^  Question- Cojnpends ,  page  21.] 

"  This  work,  already  excellent  in  the  old  edition,  has  been  largely  improved  by  revi- 
sion." — American  Practitioner  and  News. 

MORRIS,  WOLFF,  AND  POWELL'S  PRACTICE  OF  MEDICINE. 
Third  Edition,  Revised. 
Essentials  of  the  Practice  of  Medicine.  By  Henry  Morris,  M.D., 
late  Demonstrator  of  Therapeutics,  Jefferson  Medical  College,  Phila- 
delphia ;  with  an  Appendix  on  the  Clinical  and  Microscopic  Examina- 
tion of  Urine,  by  Lawrence  Wolff,  M.D. ,  Demonstrator  of  Chemistry, 
Jefferson  Medical  College,  Philadelphia.  Enlarged  by  some  300  essen- 
tial formulae  collected  and  arranged  by  William  M.  Powell,  M.D. 
Post-octavo,  488  pages.     Cloth,  ^2.00. 

[See  Saunders^  Question- Compends,  page  21.] 

"  The  teaching  is  sound,  the  presentation  graphic  ;  matter  full  as  can  be  desired,  and 
style  attractive." — A?nerican  Practitioner  and  News. 


18  Medical  Publications  of  W.  B.  Saunders. 

MORTEN'S  NURSE'S  DICTIONARY. 

Nurse's  Dictionary  of  Medical  Terms  and  Nursing  Treat- 
ment. Containing  Definitions  of  the  Principal  Medical  and  Nursing 
Terms  and  Abbreviations ;  of  the  Instruments,  Drugs,  Diseases,  Acci- 
dents, Treatments,  Operations,  Foods,  Appliances,  etc.  encountered 
in  the  ward  or  in  the  sick-room.  By  Honnor  Morten,  author  of 
"  How  to  Become  a  Nurse,"  etc.     i6mo,  140  pages.      Cloth,  ^i.oo. 

"  A  handy,  compact  little  volume,  containing  a  large  amount  of  general  information,  all 
of  which  is  arranged  in  dictionary  or  encyclopedic  form,  thus  facilitating  quick  reference. 
It  is  certainly  of  value  to  those  for  whose  use  it  is  published." — Chicago  Clinical  Review. 

NANCREDE'S  ANATOMY.  Sixth  Edition,  Thoroughly  Revised. 
Essentials  of  Anatomy,  including  the  Anatomy  of  the  Viscera. 
By  Charles  B.  Nancrede,  M.D.,  LL.D.,  Professor  of  Surgery  and 
of  Clinical  Surgery  in  the  University  of  Michigan,  Ann  Arbor.  Crown 
octavo,  420  pages;  151  illustrations.  Based  upon  Gj'ay's  Anatomy. 
Cloth,  $1.00  net;  interleaved  for  notes,  $1.25  net. 

[See  Smitiders'  Question- Compends,  page  21.] 

"  For  self-quizzing  and  keeping  fresh  in  mind  the  knowledge  of  anatomy  gained  at 
school,  it  would  not  be  easy  to  speak  of  it  in  terms  too  favorable." — American  Practitioner. 

NANCREDE'S  ANATOMY  AND  DISSECTION.     Fourth  Edition. 
Essentials  of  Anatomy  and    Manual  of   Practical    Dissection. 

By  Charles  B.  Nancrede,  M.D.,  LL.D.,  Professor  of  Surgery  and  of 
Clinical  Surgery,  University  of  Michigan,  Ann  Arbor,  Post-octavo  ; 
500  pages,  with  full-page  lithographic  plates  in  colors,  and  nearly  200 
illustrations.     Extra  Cloth  (or  Oilcloth  for  dissection-room),  $2.00  net. 

"  It  may  in  many  respects  be  considered  an  epitome  of  Gray's  popular  work  on  general 
anatomy,  at  tlie  same  time  having  some  distinguishing  characteristics  of  its  own  to  commend 
it.  The  plates  are  of  more  than  ordinary  excellence,  and  are  of  especial  value  to  students 
in  their  work  in  the  dissecting  room." — Journal  of  the  American  ]\Iedical  Association. 

NORRIS'S  SYLLABUS  OF  OBSTETRICS.  Third  Edition,  Revised. 
Syllabus  of  Obstetrical  Lectures  in  the  Medical  Department 
of  the  University  of  Pennsylvania.  By  Richard  C.  Norris, 
A.M.,  M.D.,  Detnonstrator  of  Obstetrics,  University  of  Pennsylvania. 
Crown  octavo,  222  pages.      Cloth,  interleaved  for  notes,  $2.00  net. 

"This  work  is  so  far  superior  to  others  on  the  same  subject  that  we  take  pleasure  in 
calling  attention  briefly  to  its  excellent  features.  It  covers  the  subject  thoroughly,  and  will 
prove  invaluable  both  to  the  student  and  the  practitioner." — Medical  Record,  New  York. 

PENROSE'S  DISEASES  OF  WOMEN.     Second  Edition,  Revised. 
A  Text=Book  of  Diseases  of  Women.     By  Charles  B.  Penrose, 
M.D.,  Ph.D.,  Professor  of  Gynecology  in  the  University  of  Pennsyl- 
vania;   Surgeon    to    the   Gynecean    Hospital,    Philadelphia.     Octavo 
volume  of  529  pages,  handsomely  illustrated.     Cloth,  $3.50  net. 

*<  I  shall  value  very  highly  the  copy  of  Penrose's  '  Di.seases  of  Women'  received. 
I  have  already  recommended  it  to  my  class  as  THE  BEST  book."— Howard  A.  Kelly, 
Professor  of  Gynecology  and  Obstetrics,  Johns  Hopkins  University,  Baltimore,  Md. 

"  The  book  is  to  be  commended  without  reserve,  not  only  to  the  student  but  to  the 
general  practitioner  who  wishes  to  have  the  latest  and  best  modes  of  treatment  explained 
with  absolute  clearness." — Therapeutic  Gazette. 


Medical  Publications  of  W.  B.  Saunders.  19 

POWELL'S  DISEASES  OF  CHILDREN.     Second  Edition. 

Essentials  of  Diseases  of  Children.  By  William  M.  Powell, 
M.D.,  Attending  Physician  to  the  Mercer  House  for  Invalid  Women 
at  Atlantic  City,  N.  J.  ;  late  Physician  to  the  Clinic  for  the  Diseases  of 
Children  in  the  Hospital  of  the  University  of  Pennsylvania.  Crown 
octavo,  222  pages.     Cloth,  ^i.oo;  interleaved  for  notes,  ^1.25. 

[See  Saunders'  Question- Compends,  page  21.] 

"  Contains  the  gist  of  all  the  best  works  in  the  department  to  which  it  relates." — 
American  Practitioner  and  Netvs. 

PRINQLE'S  SKIN  DISEASES  AND  SYPHILITIC  AFFECTIONS. 
Pictorial  Atlas  of  Skin  Diseases  and  Syphilitic  Affections 
(American  Edition).  Translation  from  the  French.  Edited  by 
J.  J.  Pringle,  M.B.,  F.R.C.P.,  Assistant  Physician  to  the  Middlesex 
Hospital,  London.  Photo-lithochromes  from  the  famous  models  in 
the  Museum  of  the  Saint-Louis  Hospital,  Paris,  with  explanatory  wood- 
cuts and  text.  In  12  Parts.  Price  per  Part,  $3.00.  Complete  in 
one  volume,  Half  Morocco  binding,  ^40.00  net. 

"I  strongly  recommend  this  Atlas.  The  plates  are  exceedingly  well  executed,  and 
will  be  of  great  value  to  all  studying  dermatology." — Stephen  Mackenzie,  M.D. 

"The  introduction  of  explanatory  wood-cuts  in  the  text  is  a  novel  and  most  important 
feature  which  greatly  furthers  the  easier  understanding  of  the  excellent  plates,  than  which 
nothing,  we  venture  to  say,  has  been  seen  better  in  point  of  correctness,  beauty,  and  general 
merit." — New  York  Medical  Jourtial. 

PRYOR— PELVIC  INFLAMMATIONS. 

The  Treatment  of   Pelvic  Inflammations  through  the  Vagina. 

By  W.  R.  Pryor,  M.D.,  Professor  of  Gynecology  in  New  York  Poly- 
clinic.     i2mo,  248  pages,  handsomely  illustrated.      Cloth,  ^2.00  net. 

"This  subject,  which  has  recently  been  so  thoroughly  canvassed  in  high  gynecological 
circles,  is  made  available  in  this  volume  to  the  general  practitioner  and  student.  Nothing  is 
too  minute  for  mention  and  nothing  is  taken  for  granted  ;  consequently  the  book  is  of  the  utmost 
value.    The  illustrations  and  the  technique  are  beyond  criticism." — Chicago  Medical  Recorder. 

PYE'S  BANDAGING. 

Elementary  Bandaging  and  Surgical  Dressing.  With  Direc- 
tions concerning  the  Immediate  Treatment  of  Cases  of  Emergency. 
For  the  use  of  Dressers  and  Nurses.  By  Walter  Pye,  F.R.C.S.,  late 
Surgeon  to  St.  Mary's  Hospital,  London.  Small  121110,  with  over  80 
illustrations.      Cloth,  flexible  covers,  75  cents  net. 

"The  directions  are  clear  and  the  illustrations  are  good." — London  Lancet. 
"  The  author  writes  well,  the  diagrams  are  clear,  and  the  book  itself  is  small  and  port- 
able, although  the  paper  and  type  are  good." — British  Medical  Journal. 

RAYMOND'S  PHYSIOLOGY. 

A  Manual  of  Physiology.  By  Joseph  H.  Raymond,  A.M.,  M.D., 
Professor  of  Physiology  and  Hygiene  and  Lecturer  on  Gynecology  in 
the  Long  Island  College  Hospital ;  Director  of  Physiology  in  the 
Hoagland  Laboratory,  etc.  382  pages,  with  102  illustrations  in  the 
text,  and  4  full -page  colored  plates.     Cloth,  $1.25  net. 

"  Extremely  well  gotten  up,  and  the  illustrations  have  been  selected  with  care.  The 
text  is  fully  abreast  with  modern  physiology." — British  Medical  Journal. 


Saunders' 
Question 
compends 


Arranged  in  Question  and 
Answer  Form. 


npHE  MOST  COMPLETE  AND  BEST 
ILLUSTRATED  SERIES  OF 

COMPENDS  EVER  ISSUED. 


Now  the  Standard  Authorities  in  Medical  Literature  .... 

with  Students  and  Practitioners  in  every  City  of  the  United  States  and  Canada. 


O-- 


OVER  175,000  COPIES  SOLD.    ^ 


•<<3 


THE  REASON  WHY. 

They  are  the  advance  guard  of  "Student's  Helps" — that  DO  help.  They  are  the 
leaders  in  their  special  line,  well  and  authoritatively  written  by  able  men,  who,  as  teachers  in 
the  large  colleges,  know  exactly  what  is  wanted  by  a  student  preparing  for  his  examinations. 
The'judgment  exercised  in  the  selection  of  authors  is  fully  demonstrated  by  their  professional 
standing.  Chosen  from  the  ranks  of  Demonstrators,  Quiz-masters,  and  Assistants,  most  of 
them  have  become  Professors  and  Lecturers  in  their  respective  colleges. 

Each  book  is  of  convenient  size  (5x7  inches),  containing  on  an  average  250  pages, 
profusely  illustrated,  and  elegantly  printed  in  clear,  readable  type,  on  fine  paper. 

The  entire  series,  numbering  twenty-three  volumes,  has  been  kept  thoroughly  revised 
and  enlarged  when  necessary,  many  of  the  books  being  in  their  fifth  and  sixth  editions. 

TO  SUM  UP. 

Although  there  are  numerous  other  Quizzes,  Manuals,  Aids,  etc.  in  the  market,  none  of 
them  approach  the  "Blue  Series  of  Question  Compends;"  and  the  claim  is  made  for  the 
following  points  of  excellence  : 

1.  Professional  distinction  and  reputation  of  i^uthors. 

2.  Conciseness,  clearness,  and  soundness  of  treatment. 

3.  Quality  of  illustrations,  paper,  printing,  and  binding. 

Any  cf  these  Compends  will  be   mailed  on  receipt  of  price  (see  next  page  for  List). 


oaunders^  Question-Compend  Series^ 

Price,  Cloth,  $J.OO  per  copy,  except  when  otherwise  noted. 


"Where   the  work   of  preparing  students'  manuals   is   to  end  we   cannot  say,  but  the 
Saunders  Series,  in  our  opinion,  bears  off  the  palm  at  present."— iWw  York  Medical  Record. 


1.  ESSENTIALS  OF  PHYSIOLOGY.     By  H.  A.  Hare,  M.D.    Fourth  edition, 

revised  and  enlarged.      (^I.oo  net. ) 

2.  ESSENTIALS  OF   SURGERY.     By  Edward  Martin,  M.D.      Sixth  edition, 

revised,  with  an  Appendix  on  Antiseptic  Surgery. 

3.  ESSENTIALS   OF   ANATOMY.      By  Charles  B.   Nancrede,  M.D.      Sixth 

edition,  thoroughly  revised  and  enlarged,      (^i.oo  net.) 

4.  ESSENTIALS  OF  MEDICAL  CHEMISTRY,  ORGANIC  AND  INORGANIC. 

By  Lawrence  Wolff,  M.D.     Fifth  edition,  revised,     (^i.oo  net.) 

5.  ESSENTIALS  OF  OBSTETRICS.     By  W.  Easterly  Ashton,  M.D.     Fourth 

edition,  revised  and  enlarged. 

6.  ESSENTIALS  OF  PATHOLOGY  AND  MORBID  ANATOMY.     By  C.  E. 

Armand  Semple,  M.D. 

7.  ESSENTIALS  OF  MATERIA  MEDICA,  THERAPEUTICS,  AND  PRE- 

SCRIPTION=WRITING.    By  Henry  Morris,  M.D.       Fifth  edition,  revised. 

8.  9.   ESSENTIALS   OF   PRACTICE   OF   MEDICINE.     By  Henry  Morris, 

M.D.  An  Appendix  on  Urine  Examination.  By  Lawrence  Wolff,  M.D. 
Third  edition,  enlarged  by  some  300  Essential  Formulae,  selected  from  eminent 
authorities,  by  Wm.  M.  Powell,  M.D.      (Double  number,  ^2.00.) 

10.    ESSENTIALS  OF  QYN/ECOLOQY.      By  Edwin  B.  Cragin,  M.D.      Fourth 
edition,  revised. 

1  \ .   ESSENTIALS  OF  DISEASES  OF  THE  SKIN.     By  Henry  W.  Stelwagon, 
M.D.     Fourth  edition,  revised  and  enlarged,     (^i.oo  net.) 

12.  ESSENTIALS  OF  MINOR  SURGERY,  BANDAGiNG,  AND  VENEREAL 

DISEASES.     By  Edward  Martin,  M.D.     Second  ed. ,  revised  and  enlarged. 

13.  ESSENTIALS  OF  LEGAL  MEDICINE,  TOXICOLOGY,  AND  HYGIENE. 

By  C.  E.  Armand  Semple,  M.D. 

14.  ESSENTIALS  OF  DISEASES  OF  THE   EYE,  NOSE,  AND  THROAT. 

By  Edward  Jackson,  M.D.,  and  E.  B.  Gleason,  M.D.     Second  ed.,  revised. 

15.  ESSENTIALS  OF  DISEASES  OF  CHILDREN.     By  William  M.  Powell, 

M.D.     Second  edition. 

16.  ESSENTIALS  OF   EXAMINATION   OF  URINE.     By  Lawrence  Wolff, 

M.D.     Colored  "  Vogel  Scale."     (75  cents.) 

17.  ESSENTIALS  OF  DIAGNOSIS.     By  S.  Solis  Cohen,  M.D.,  and  A.  A.  Eshner, 

M.D.     (|i.5onet.) 

18.  ESSENTIALS  OF  PRACTICE   OF   PHARMACY.     By  Lucius   E.    Sayre. 

Second  edition,  revised  and  enlarged. 

20.  ESSENTIALS  OF  BACTERIOLOGY.     By  M.  V.  Ball,  M.D.     Third  edition, 

revised. 

21.  ESSENTIALS  OF  NERVOUS  DISEASES  AND  INSANITY.     By  John  C. 

Shaw-,  M.D.     Third  edition,  revised. 

22.  ESSENTIALS  OF   MEDICAL  PHYSICS.      By  Fred  J.    Brockway,    M.D. 

Second  edition,  revised.      ($1.00  net.) 

23.  ESSENTIALS  OF  MEDICAL  ELECTRICITY.    By  David  D.  Stewart,  M.D., 

and  Edward  S.  Lawrance,  M.D. 

24.  ESSENTIALS  OF  DISEASES  OF  THE   EAR.      By  E.  B.  Gleason,  M.D. 

Second  edition,  revised  and  greatly  enlarged. 


Pamphlet  containing  specimen  pages,  etc.  sent  free  upon  application* 


Saunders*  re... 

tor  jtudents 

New  Series  and 

of    Manuals  Practitioners. 


'  I  'HAT  there  exists  a  need  for  thoroughly  reliable  hand-books  on  the  leading  branches 
of  Medicine  and  Surgery  is  a  fact  amply  demonstrated  by  the  favor  with  -which 
the  SAUNDERS  NE'W  SERIES  OF  MANUALS  have  been  received  by  medical 
students  and  practitioners  and  by  the  Medical  Press.  These  manuals  are  not  merely 
condensations  from  present  literature,  but  are  ably  written  by  well-known  authors 
and  practitioners,  most  of  them  being  teachers  in  representative  American  colleges. 
Each  volume  is  concisely  and  authoritatively  w^ritten  and  exhaustive  in  detail,  without 
being  encumbered  w^ith  the  introduction  of  "cases,"  which  so  largely  expand  the 
ordinary  text-book.  These  manuals  will  therefore  form  an  admirable  collection  of 
advanced  lectures,  useful  alike  to  the  medical  student  and  the  practitioner:  to  the 
latter,  too  busy  to  search  through  page  after  page  of  elaborate  treatises  for  what  he 
wants  to  know^,  they  w^ill  prove  of  inestimable  value ;  to  the  former  they  will  afford 
safe  guides  to  the  essential  points  of  study. 

The  SAUNDERS  NEW  SERIES  OF  MANUALS  are  conceded  to  be  superior 
to  any  similar  books  now^  on  the  market.  No  other  manuals  afford  so  much  infor- 
mation in  such  a  concise  and  available  form.  A  liberal  expenditure  has  enabled  the 
publisher  to  render  the  mechanical  portion  of  the  w^ork  worthy  of  the  high  literary 
standard  attained  by  these  books. 

Any  of  these  Manuals  w^ill  be  mailed  on  receipt  of  price  (see  next  page  for  List). 


Saunders^  New  Series  of  Manuals* 


VOLUMES   PUBLISHED. 

PHYSIOLOGY.  By  Joseph  Howard  Raymond,  A.M.,  M.D.,  Professor  of  Physiology 
and  Hygiene  and  Lecturer  on  Gynecology  in  the  Long  Island  College  Hospital ; 
Director  of  Physiology  in  the  Hoagland  Laboratory,  etc.     Illustrated.     Cloth,  $1.25  net. 

SURGERY,  General  and  Operative.  By  John  Chalmers  DaCosta,  M.D.,  Clini- 
cal Professor  of  Surgery,  Jefi'erson  Medical  College,  Philadelphia;  Surgeon  to  the 
Philadelphia  Hospital,  etc.  Second  edition,  thoroughly  revised  and  greatly  enlarged. 
Octavo,  911  pages,  profusely  illustrated.      Cloth,  $4.00  net ;   Half  Morocco,  $5.00  net. 

DOSE=BOOK    AND    MANUAL    OF    PRESCRIPTION=WRITING.      By   E.    Q. 

Thornton,  M.D.,  Demonstrator  of  Therapeutics,  Jefferson  Medical  College,  Phila- 
delphia.    Illustrated.      Cloth,  ^1.25  net. 

SURGICAL  ASEPSIS.  By  Carl  Beck,  M.D.,  Surgeon  to  St.  Mark's  Hospital  and 
to  the  New  York  German  Poliklinik,  etc.      Illustrated.      Cloth,  ^1.25  net. 

MEDICAL  JURISPRUDENCE.  By  Henry  C.  Chapman,  M.D.  Professor  of  Insti- 
tutes of  Medicine  and  Medical  Jurisprudence  in  the  Jefferson  Medical  College  of  Phila- 
delphia.    Illustrated.     Cloth,  ^1.50  net. 

SYPHILIS  AND  THE  VENEREAL  DISEASES.  By  James  Nevins  Hyde,  M.D., 
Professor  of  Skin  and  Venereal  Diseases,  and  Frank  H.  Montgomery,  M.D., 
Lecturer  on  Dermatology  and  Genito-Urinary  Diseases  in  Rush  Medical  College, 
Chicago.      Profusely  illustrated.     Cloth,  ^2.50  net. 

PRACTICE  OF  MEDICINE.  By  George  Roe  Lockwood,  M.D.,  Professor  of 
Practice  in  the  Woman's  Medical  College  of  the  New  York  Infirmary ;  Instructor  in 
Physical  Diagnosis  in  the  Medical  Department  of  Columbia  College,  etc.  Illustrated. 
Cloth,  ^2.50  net. 

MANUAL  OF  ANATOMY.  By  Irving  S.  Haynes,  M.D.,  Adjunct  Professor  of 
Anatomy  and  Demonstrator  of  Anatomy,  Medical  Department  of  the  New  York 
University,  etc.     Beautifully  illustrated.     Cloth,  ^2.50  net. 

MANUAL  OF  OBSTETRICS.  By  W.  A.  Newman  Dorland,  M.D.,  Assistant 
Demonstrator  of  Obstetrics,  University  of  Pennsylvania ;  Chief  of  Gynecological  Dis- 
pensary, Pennsylvania  Hospital,  etc.     Profusely  illustrated.     Cloth,  ^2.50  net. 

DISEASES  OF  WOMEN.  By  J.  Bland  Sutton,  F.  R.  C.  S.,  Assistant  Surgeon  to 
Middlesex  Hospital  and  Surgeon  to  Chelsea  Hospital,  London;  and  Arthur  E. 
Giles,  M.  D.,  B.  Sc.  Lond.,  F.R.C.S.  Edin.,  Assistant  Surgeon  to  Chelsea  Hospital, 
London.     Handsomely  illustrated.     Cloth,  ^2.50  net. 


VOLUMES  IN  PREPARATION. 

NERVOUS  DISEASES.  By  Charles  W.  Burr,  M.D.,  Clinical  Professor  of  Nervous 
Diseases,  Medico- Chirurgical  College,  Philadelphia ;  Pathologist  to  the  Orthopaedic 
Hospital  and  Infirmary  for  Nervous  Diseases ;  Visiting  Physician  to  the  St.  Joseph 
Hospital,  etc. 

***  There  will  be  published  in  the  same  series,  at  short  intervals,  carefully-prepared  works 
on  various  subjects  by  prominent  specialists. 


Pamphlet  containiiig  specimen  pages^  etc.  sent  free  upon  application. 


24  Medical  Publications  of  W,  B.  Saunders. 

SAUNDBY'S  RENAL  AND  URINARY  DISEASES. 

Lectures  on  Renal  and  Urinary  Diseases.  By  Robert  Saundby, 
M.D.  Edin.,  Fellow  of  the  Royal  College  of  Physicians,  London,  and 
of  the  Royal  Medico-Chirurgical  Society  ;  Physician  to  the  General 
Hospital ;  Consulting  Physician  to  the  Eye  Hospital  and  to  the  Hos- 
pital for  Diseases  of  Women;  Professor  of  Medicine  in  Mason  College, 
Birmingham,  etc.  Octavo  volume  of  434  pages,  with  numerous  illus- 
trations and  4  colored  plates.     Cloth,  $2.50  net. 

"  The  volume  makes  a  favorable  impression  at  once.  The  style  is  clear  and  succinct. 
"We  cannot  find  any  part  of  the  subject  in  which  the  views  expressed  are  not  carefully  thought 
out  and  fortified  by  evidence  drawn  from  the  most  recent  sources.  The  book  may  be  cordially 
recommended." — British  Medical  Journal. 

5AUNDERS'  MEDICAL  HAND=ATLASES. 

This  series  of  books  consists  of  authorized  translations  into  English  of 
the  world-famous   Lehmann   Medicinische   Handatlanten.     Each 

volume  contains  from  50  to  100  colored  lithographic  plates,  besides 
numerous  illustrations  in  the  text.  There  is  a  full  description  of  each 
plate,  and  each  book  contains  a  condensed  but  adequate  outline  of  the 
subject  to  which  it  is  devoted.  For  full  description  of  this  series,  with 
list  of  volumes  and  prices,  see  page  2. 

"  Lehmann  Medicinische  Handatlanten  belong  to  that  class  of  books  that  are  too  good 
to  be  appropriated  by  any  one  nation." — jfournal  of  Eye,  Ear,  and  Throat  Diseases. 

"  The  appearance  of  these  works  marks  a  new  era  in  illustrated  English  medical 
works." — The  Canadian  Practitioner. 

SAUNDERS'   POCKET  MEDICAL   FORMULARY.      Fifth   Edition, 
Revised. 

By  William  M.  Powell,  M.D.,  Attending  Physician  to  the  Mercer 
House  for  Ihvalid  Women  at  Atlantic  City,  N.  J.  Containing  1800 
formulae  selected  from  the  best-known  authorities.  With  an  Appen- 
dix containing  Posological  Table,  Formulae  and  Doses  for  Hypo- 
dermic Medication,  Poisons  and  their  Antidotes,  Diameters  of  the 
Female  Pelvis  and  Fcetal  Head,  Obstetrical  Table,  Diet  List  for  Various 
Diseases,  Materials  and  Drugs  used  in  Antiseptic  Surgery,  Treatment 
of  Asphyxia  from  Drowning,  Surgical  Remembrancer,  Tables  of 
Incompatibles,  Eruptive  Fevers,  Weights  and  Measures,  etc.  Hand- 
somely bound  in  flexible  morocco,  with  side  index,  wallet,  and  flap. 
$1.75  net. 

"This  little  book,  that  can  be  conveniently  carried  in  the  pocket,  contains  an  immense 
amount  of  material.  It  is  very  useful,  and,  as  the  name  of  the  author  of  each  prescription 
is  given,  is  unusually  reliable." — Medical  Record,  New  York. 

SAYRE'S  PHARMACY.     Second  Edition,  Revised. 

Essentials  of  the  Practice  of  Pharmacy,  By  Lucius  E.  Sayre, 
M.D.,  Professor  of  Pharmacy  and  Materia  Medica  in  the  University  of 
Kansas.  Crown  octavo,  200  pages.  Cloth,  ^i.oo;  interleaved  for 
notes,  $1.25. 

[See  Saufiders^  Question- Compends,  page  21.] 

"The  topics  are  treated  in  a  simple,  practical  manner,  and  the  work  forms  a  very  useful 
student's  manual." — Boston  Medical  and  Surgical  Journal. 


Medical  Publications  of  W.  B.  Saunders.  25 

SEMPLE'S  LEGAL  MEDICINE,  TOXICOLOGY,  AND  HYGIENE. 
Essentials  of   Legal   Medicine,  Toxicology,  and  Hygiene.     By 

C.  E.  Armand  Semple,  B.  A.,  M.  B.  Cantab.,  M.  R.  C.  P.  Lend., 
Physician  to  the  Northeastern  Hospital  for  Children,  Hackney,  etc. 
Crown  octavo,  2  12  pages;  130  illustrations.  Cloth,  ^i. 00;  interleaved 
for  notes,  ^1.25. 

[See  Saunde7's    Question- Coiiipends,  page  21.] 

"  No  general  practitioner  or  student  can  afford  to  be  without  this  valuable  work.  The 
subjects  are  dealt  with  by  a  masterly  hand." — London  Hospital  Gazette. 

SEMPLE'S  PATHOLOGY  AND  MORBID  ANATOMY. 

Essentials    of    Pathology    and    Morbid    Anatomy.      By  C.   E. 

Armand  Semple,  B.A.,  M.B.  Cantab.,  M.R.C.P.  Lond.,  Physician  to 
the  Northeastern  Hospital  for  Children,  Hackney,  etc.     Crown  octavo, 
174  pages;  illustrated.      Cloth,  $1.00;  interleaved  for  notes,  ^1.25. 
[See  Saunders'  Question- Compends,  page  21.] 

"  Should  take  its  place  among  the  standard  volumes  on  the  bookshelf  of  both  student 
and  practitioner." — London  Hospital  Gazette. 

SENN'S  GENITO=URINARY  TUBERCULOSIS. 

Tuberculosis  of  the  Genito=Urinary  Organs,  Male  and  Female. 

By  Nicholas  Senn,  M.D.,  Ph.D.,  LL.D.,  Professor  of  the  Practice  of 
Surgery  and  of  Clinical  Surgery,  Rush  Medical  College,  Chicago. 
Handsome  octavo  volume  of  320  pages,  illustrated.      Cloth,  ^3.00  net. 

"  An  important  book  upon  an  important  subject,  and  written  by  a  man  of  mature  judg- 
ment and  wide  experience.  The  author  has  given  us  an  instructive  book  upon  one  of  the 
most  important  subjects  of  the  day." — Clinical  Reporter. 

"  A  work  which  adds  another  to  the  many  obligations  the  profession  owes  the  talented 
author." — Chicago  Medical  Recorder. 

SENN'S  SYLLABUS  OF  SURGERY. 

A  Syllabus  of  Lectures  on  the  Practice  of  Surgery,  arranged 
in  conformity  with  "  An  American  Text=Book  of  Surgery."    By 

Nicholas  Senn,  M.D.,  Ph.D.,  Professor  of  the  Practice  of  Surgery  and 
of  Clinical  Surgery  in  Rush  Medical  College,  Chicago.     Cloth,  ^2.00. 

"  This  syllabus  will  be  found  of  service  by  the  teacher  as  well  as  the  student,  the  work 
being  superbly  done.  There  is  no  praise  too  high  for  it.  No  surgeon  should  be  without 
it." — Nezv  York  Medical  Times. 

SENN'S  TUMORS. 

Pathology  and  Surgical  Treatment  of  Tumors.     By  N.  Senn, 

M.D.,  Ph.D.,  LL.D.,  Professor  of  Surgery  and  of  Clinical  Surgery, 
Rush  Medical  College ;  Professor  of  Surgery,  Chicago  Polyclinic ; 
Attending  Surgeon  to  Presbyterian  Hospital ;  Surgeon-in-Chief,  St. 
Joseph's  Hospital,  Chicago.  Octavo  volume  of  710  pages,  with  515 
engravings,  including  full-page  colored  plates.  New  and  Revised  Edi- 
tion in  Preparation. 

"  The  most  exhaustive  of  any  recent  book  in  Ergnsh  on  this  subject.  It  is  well  illus- 
trated, and  will  doubtless  remain  as  the  principal  monograph  on  the  subject  in  our  language 
for  some  years.  The  book  is  handsomely  illustrated  and  printed,  and  the  author  has  given  a 
notable  and  lasting  contribution  to  surgery." — Journal  of  the  Ame7-ican  Medical  Association. 


26  Medical  Publications  of  W.  B.  Saunders. 

SHAW'S  NERVOUS  DISEASES  AND  INSANITY.  Third  Edition, 
Revised. 
Essentials  of  Nervous  Diseases  and  Insanity.  By  John  C. 
Shaw,  M.D.,  Clinical  Professor  of  Diseases  of  the  Mind  and  Nervous 
System,  Long  Island  College  Hospital  Medical  School ;  Consulting 
Neurologist  to  St.  Catherine's  Hospital  and  to  the  Long  Island  College 
Hospital.  Crown  octavo,  i86  pages;  48  original  illustrations.  Cloth, 
^i.oo  ;  interleaved  for  notes,  ^1.25. 

[See  Saunders''  Question- Compends,  page   21.] 

"Clearly  and  intelligently  written." — Bosto7i  Medical attd  Surgical Jownal. 

"There  is  a  mass  of  valuable  material  crowded  into  this  small  compass." — American- 
Medico-  Sta-gical  Bulletin. 

STARR'S  DIETS  FOR  INFANTS  AND  CHILDREN. 

Diets  for  Infants  and  Children  in  Health  and  in  Disease.     By 

Louis  Starr,  M.D.,  Editor  of  "An  American  Text-Book  of  the 
Diseases  of  Children."  230  blanks  (pocket-book  size),  perforated 
and  neatly  bound  in  flexible  morocco.      ^1.25  net. 

The  first  series  of  blanks  are  prepared  for  the  first  seven  months  of  infant  life  ;  each 
blank  indicates  the  ingredients,  but  not  the  quantities,  of  the  food,  the  latter  directions  being 
left  for  the  physician.  After  the  seventh  month,  modifications  being  less  necessary,  the  diet 
lists  are  printed  in  full.      Formulae  for  the  preparation  of  diluents  and  foods  are  appended. 

STELW AGON'S  DISEASES  OF  THE  SKIN.     Fourth  Ed.,  Revised. 

Essentials  of  Diseases  of  the  Skin.  By  Henry  W.  Stelwagon, 
M.D.,  Clinical  Professor  of  Dermatology  in  the  Jefferson  Medical 
College,  Philadelphia ;  Dermatologist  to  the  Philadelphia  Hospital ; 
Physician  to  the  Skin  Department  of  the  Howard  Hospital,  etc. 
Crown  octavo,  276  pages;  88  illustrations.  Cloth,  ^i. 00  net;  inter- 
leaved for  notes,  $1.25  net. 

[See  Saunde7's'  Question-Compends,  page  21.] 

"  The  best  student's  manual  on  skin  diseases  we  have  yet  seen." — Times  and  Register^ 

STENGEL'S  PATHOLOGY.      Second  Edition. 

A  Text=Book  of  Pathology.  By  Alfred  Stengel,  M.D.,  Professor 
of  Clinical  Medicine  in  the  University  of  Pennsylvania;  Physician  to 
the  Philadelphia  Hospital  ;  Physician  to  the  Children's  Hospital,  etc. 
Handsome  octavo  volume  of  848  pages,  with  nearly  400  illustrations, 
many  of  them  in  colors.  Cloth,  $4.00  net;  Half  Morocco,  $5.00 
net. 

STEVENS'   MATERIA    MEDICA   AND   THERAPEUTICS.      Second 
Edition,  Revised. 
A  Manual  of   Materia   Medica   and  Therapeutics.      By  A.  A. 

Stevens,  A.M.,   M.D.,  Lecturer  on  Terminology  and    Instructor  in 
Physical  Diagnosis   in  the  University  of  Pennsylvania;    Professor  of 
Pathology  in  the  Woman's  Medical  College  of  Pennsylvania.     Post- 
octavo,  445  pages.     Flexible  leather,  $2.25. 
««The  author  has  faithfully  iiresented  modern  therapeutics  in  a  comprehensive  work, 
and,  while  intended  particularly  for  the  use  of  students,  it  will  be  found  a  reliable  guide  and 
sufficiently  comprehensive  for  the  physician  in  practice." — University  Medical  Magazitte. 


Medical  Publications  of  W.  B.  Saunders.  27 


STEVENS'  PRACTICE  OF  MEDICINE.     Fifth  Edition,  Revised. 
A  Manual  of  the  Practice  of  Medicine.     By  A.  A.  Stevens,  A.  M., 

M.  D.,  Lecturer  on  Terminology  and  Instructor  in  Physical  Diagnosis 
in  the  University  of  Pennsylvania;  Professor  of  Pathology  in  the 
Woman's  Medical  College  of  Pennsylvania.  Specially  intended  for 
students  preparing  for  graduation  and  hospital  examinations.  Post- 
octavo,  519  pages ;   illustrated.     Flexible  leather,  ^2.00  net. 

"  The  frequency  with  which  new  editions  of  this  manual  are  demanded  bespeaks  its 
popularity.  It  is  an  excellent  condensation  of  the  essentials  of  medical  practice  for  the 
student,  and  maybe  found  also  an  excellent  reminder  for  the  busy  physician." — Btiffalo 
Medical  Journal. 

STEWART'S  PHYSIOLOGY.      Third  Edition,  Revised. 

A  Manual  of  Physiology,  with  Practical  Exercises.  For 
Students  and  Practitioners.  By  G.  N.  Stewart,  M.A.,  M.D., 
D.Sc,  lately  Examiner  in  Physiology,  University  of  Aberdeen,  and 
of  the  New  Museums,  Cambridge  University ;  Professor  of  Physiology 
in  the  Western  Reserve  University,  Cleveland,  Ohio.  Octavo  volume 
of  848  pages;  300  illustrations  in  the  text,  and  5  colored  plates. 
Cloth,  $3.75  net. 

"  It  will  ma,ke  its  way  by  sheer  force  of  merit,  and  amply  deserves  to  do  so.  It  is  one 
of  the  very  best  English  text-books  on  the  subject." — London  Lancet. 

"Of  the  many  text-books  of  physiology  published,  we  do  not  know  of  one  that  so 
nearly  comes  up  to  the  ideal  as  does  Prof.  Stewart's  volume." — British  Medical  Journal. 

STEWART  AND  LAWRANCE'S  MEDICAL  ELECTRICITY. 

Essentials  of  Medical  Electricity.  By  D.  D.  Stewart,  M.D., 
Demonstrator  of  Diseases  of  the  Nervous  System  and  Chief  of  the 
Neurological  Clinic  in  the  Jefferson  Medical  College ;  and  E.  S. 
Lawrance,  M.D.,  Chief  of  the  Electrical  Clinic  and  Assistant  Demon- 
strator of  Diseases  of  the  Nervous  System  in  the  Jefferson  Medical 
College,  etc.  Crown  octavo,  158  pages;  65  illustrations.  Cloth, 
^  1 .  00  ;  interleaved  for  notes,  ^1.25. 

[See  Saundei's'  Question- Conipends,  page  21.] 

•'  Throughout  the  whole  brief  space  at  their  command  the  authors  show  a  discriminating 
knowledge  of  their  subject." — Medical  News. 

STONEY'S  NURSING.     Second  Edition,  Revised. 

Practical  Points  in  Nursing.     For  Nurses  in  Private  Practice, 

By  Emily  A.  M.  Stoney,  Graduate  of  the  Training-School  for  Nurses, 
Lawrence,  Mass.;  late  Superintendent  of  the  Training-School  for 
Nurses,  Carney  Hospital,  South  Boston,  Mass.  456  pages,  illustrated 
with  73  engravings  in  the  text,  and  8  colored  and  half-tone  plates. 
Cloth,  $1.75  net. 

"  There  are  few  books  intended  for  non-professional  readers  which  can  be  so  cordially 
endorsed  by  a  medical  journal  as  can  this  one." — Therapeutic  Gazette. 

"  This  is  a  well-written,  eminently  practical  volume,  which  covers  the  entire  range  of 
private  nursing  as  distinguished  from  hospital  nursing,  and  instructs  the  nurse  how  best  to 
meet  the  various  emergencies  which  may  arise,  and  how  to  prepare  everything  ordinarily 
needed  in  the  illness  of  her  patient." — American  Journal  of  Obstetrics  and  Diseases  of 
Women  and  Children. 

"  It  is  a  work  that  the  physician  can  place  in  the  hands  of  his  private  nurses  with  the 
assurance  of  benefit." — Ohio  Medical  Journal. 


28  Medical  Publications  of  W.  B.  Saunders. 


STONEY'S  MATERIA  MEDICA   FOR  NURSES. 

Materia  Medica  for  Nurses.  By  Emily  A.  M.  Stoney,  Graduate  of 
the  Training-School  for  Nurses,  Lawrence,  Mass.  ;  late  Superintendent 
of  the  Training-School  for  Nurses,  Carney  Hospital,  South  Boston,  Mass. 
Handsome  octavo  volume  of  306  pages.      Cloth,  ^1.50  net. 

The  present  book  differs  from  other  similar  works  in  several  features,  all  of  which  are 
intended  to  render  it  more  practical  and  generally  useful.  The  general  plan  of  the  contents 
follows  the  lines  laid  down  in  training-schools  for  nurses,  but  the  book  contains  much  use- 
ful matter  not  usually  included  in  works  of  this  character,  such  as  Poison-emergencies, 
Ready  Dose-list,  Weights  and  Measures,  etc.,  as  well  as  a  Glossary,  defining  all  the  terms 
used  in  Materia  Medica,  and  describing  all  the  latest  drugs  and  remedies,  which  have  been 
generally  neglected  by  other  books  of  the  kind. 

SUTTON  AND  GILES'  DISEASES  OF  WOMEN. 

Diseases  of  Women.  By  J.  Bland  Sutton,  F.R.C.S.,  Assistant 
Surgeon  to  Middlesex  Hospital,  and  Surgeon  to  Chelsea  Hospital, 
London;  and  Arthur  E.  Giles,  M.D.,  B.Sc.  Lond.,  F.R.C.S.  Edin., 
Assistant  Surgeon  to  Chelsea  Hospital,  London.  436  pages,  hand- 
somely illustrated.  Cloth,  ^2.50  net. 
"The  text  has  been  carefully  prepared.     Nothing  essential  has  been  omitted,  and  its 

teachings  are  those  recommended  by  the  leading  authorities  of  the  Asy."— Journal  of  the 

Americati  Medical  Association. 

THOMAS'S  DIET  LISTS  AND  SICK=ROOM  DIETARY. 

Diet  Lists  and  Sick=Room  Dietary.  By  Jerome  B.  Thomas, 
M.D.,  Visiting  Physician  to  the  Home  for  Friendless  Women  and 
Children  and  to  the  Newsboys'  Home;  Assistant  Visiting  Physician 
to  the  Kings  County  Hospital.     Cloth,  $1.50.     Send  for  sample  sheet. 

THORNTON'S  DOSE=BOOK  AND  PRESCRIPTION=WRITING. 

Dose=Book  and  Manual  of   Prescription=Writing.      By   E.    Q. 

Thornton,  M.D.,  Demonstrator  of  Therapeutics,  Jefferson  Medical 
College,  Philadelphia.      334  pages,  illustrated.      Cloth,  $1.25  net. 

"  Full  of  practical  suggestions;  will  take  its  place  in  the  front  rank  of  works  of  this 
sort." — Medical  Record,  New  York. 

VAN  VALZAH  AND  NISBET'S  DISEASES  OF  THE  STOMACH. 
Diseases  of  the  Stomach.  By  William  W.  Van  Valzah,  M.D., 
Professor  of  General  Medicine  and  Diseases  of  the  Digestive  System 
and  the  Blood,  New  York  Polyclinic;  and  J.  Douglas  Nisbet,  M.D., 
Adjunct  Professor  of  General  Medicine  and  Diseases  of  the  Digestive 
System  and  the  Blood,  New  York  Polyclinic.  Octavo  volume  of  674 
pages,  illustrated.     Cloth,  ^3.50  net. 

"  Its  chief  claim  lies  in  its  clearness  and  general  adaptability  to  the  practical  needs  of 
the  general  prnctitioner  or  sturient.  In  these  relations  it  is  probaljly  the  best  of  the  recent 
special  works  on  diseases  of  the  stomach." — Chicago  Clinical  Review. 

VECKI'S   SEXUAL   IMPOTENCE. 

The  Pathology  and  Treatment  of  Sexual  Impotence.  By  Victor 
G.  Veckj,  M  D.  From  the  second  German  edition,  revised  and  en- 
larged.    Demi-octavo,  about  300  pages.     Cloth,  ^2.00  net. 

The  subject  of  impotence  has  seldom  been  treated  in  this  country  in  the  truly  scientific 
spirit  that  it  deserves.  Dr.  Vecki's  work  has  long  been  favorably  known,  and  tlie  German 
book  has  received  the  highest  consideration.  This  edition  is  more  than  a  mere  translation, 
for,  although  based  on  the  German  edition,  it  has  been  entirely  rewritten  in  English. 


Medical  Publications  of  W.  B.  Saunders.  29 


VIERORDT'S  MEDICAL  DIAGNOSIS.  Fourth  Edition,  Revised. 
Medical  Diagnosis.  By  Dr.  Oswald  Vierordt,  Professor  of  Medi- 
cine at  the  University  of  Heidelberg.  Translated,  with  additions, 
from  the  fifth  enlarged  German  edition,  with  the  author's  permission, 
by  Francis  H.  Stuart,  A.  M.,  M.  D.  Handsome  royal  octavo  volume 
of  603  pages;  194  fine  wood-cuts  in  text,  many  of  them  in  colors. 
Cloth,  ^4.00  net;  Sheep  or  Half  Morocco,  ^5-oo  net. 

"  A  treasury  of  practical  information  which  will  be  found  of  daily  use  to  every  busy 
practitioner  who  will  consult  it." — C.  A.  Lindsley,  M.D.,  Professor  of  the  Theory  and 
Practice  of  Medicine,   Yale  University . 

"  Rarely  is  a  book  published  with  which  a  reviewer  can  find  so  little  fault  as  with  the 
volume  before  us.  Each  particular  item  in  the  consideration  of  an  organ  or  apparatus,  which 
is  necessary  to  determine  a  diagnosis  of  any  disease  of  that  organ,  is  mentioned ;  nothing 
seems  forgotten.  The  chapters  on  diseases  of  the  circulatory  and  digestive  apparatus  and 
nervous  system  are  especially  full  and  valuable.  The  reviewer  would  repeat  that  the  book  is 
one  of  the  best — probably  the  best — which  has  fallen  into  his  hands." — University  Medical 
Magazine. 

WARREN'S  SURGICAL  PATHOLOGY  AND  THERAPEUTICS. 

Surgical  Pathology  and  Therapeutics.  By  John  Collins  Warren, 
M.D.,  LL.D.,  Professor  of  Surgery,  Medical  Department  Harvard 
University;  Surgeon  to  the  Massachusetts  General  Hospital,  etc. 
Handsome  octavo  volume  of  832  pages;  136  relief  and  lithographic 
illustrations,  33  of  which  are  printed  in  colors,  and  all  of  which  were 
drawn  by  William  J.  Kaula  from  original  specimens.  Revised  and 
Enlarged  Edition  in  Preparation. 

"There  is  the  work  of  Dr.  Warren,  which  I  think  is  the  most  creditable  book  on 
Surgical  Pathology,  and  the  most  beautiful  medical  illustration  of  the  bookmaker's  art,  that 
has  ever  been  issued  from  the  American  press." — Dr.  Roswell  Park,  in  the  Harvard 
Graduate  Magazine. 

"  The  handsomest  specimen  of  bookmaking  that  has  ever  been  issued  from  the  American 
medical  press." — American  Journal  of  the  Medical  Sciences. 

"  A  most  striking  and  very  excellent  feature  of  this  book  is  its  illustrations.  Without 
exception,  from  the  point  of  accuracy  and  artistic  merit,  they  are  the  best  ever  seen  in  a  work 
of  this  kind.  Many  of  those  representing  microscopic  pictures  are  so  perfect  in  their  coloring 
and  detail  as  almost  to  give  the  beholder  the  impression  that  he  is  looking  down  the  barrel 
of  a  microscope  at  a  well-mounted  section." — Annals  of  Surgery. 

WOLFF  ON  EXAMINATION  OF  URINE. 

Essentials  of  Examination  of  Urine.  By  Lawrence  Wolff,  M.D., 
Demonstrator  of  Chemistry,  Jefferson  Medical  College,  Philadelphia, 
etc.  Colored  (Vogel)  urine  scale  and  numerous  illustrations.  Crown 
octavo.      Cloth,  75  cents. 

[See  Saunders'  Question- Compends ,  page   21.] 
"  A  very  good  work  of  its  kind — very  well  suited  to  its  purpose." — Titnes  and  Register. 

WOLFF'S  MEDICAL  CHEMISTRY.     Fifth  Edition,  Revised. 

Essentials    of    Medical    Chemistry,   Organic    and    Inorganic. 

Containing  also  Questions  on  Medical  Physics,  Chemical  Physiology, 
Analytical  Processes,  Urinalysis,  and  Toxicology.  By  Lawrence 
Wolff,  M.D.,  Demonstrator  of  Chemistry,  Jefferson  Medical  College, 
Philadelphia,  etc.  Crown  octavo,  222  pages.  Cloth,  ^i.oo  net;  inter- 
leaved for  notes,  ^1.25  net. 

[See  Saunders'  Question- Comf  ends,  page   21.] 

"The  scope  of  this  work  is  certainly  equal  to  that  of  the  best  course  of  lectures  on 
Medical  Chemistry." — Pharmaceutical  Era. 


CLASSIFIED    LIST 


Medical  Publications 


W.  B.  SAUNDERS, 

925  "Walnut  Street,  Philadelphia. 


ANATOMY,  EMBRYOLOGY, 
HISTOLOGY. 

Clarkson — A  Text-Book  of  Histology,  9 
Haynes — A  Manual  of  Anatomy, ...  13 
Heisler — A  Text-Book  of  Embryology,  I3 
Nancrede — Essentials  of  Anatomy,  .  .  18 
Nancrede — Essentials 'of  Anatomy  and 

Manual  of  Practical  Dissection,  .  .  .  18 
Sample — Essentials   of   Pathology  and 

Morbid  Anatomy, 25 

BACTERIOLOGY. 

Ball — Essentials  of  Bacteriology,  ...      6 
Crookshank — A  Text- Book  of  Bacteri- 
ology,   10 

Frothingham— Laboratory  Guide,  .  .  II 
Mallory   and    Wright  —  Pathological 

Technique, 16 

McFarland — Pathogenic  Bacteria,    .    .    17 

CHARTS,  DIET-LISTS,  ETC. 

Griffith— Infant's  Weight  Chart,     ...  12 

Hart — Diet  in  Sickness  and  in  Health,  .  13 

Keen — Operation  Blanlc, 15 

Laine — Temperature  Chart 15 

Meigs — Feeding  in  Early  Infancy,     .    .  17 

Starr — Diets  for  Infants  and  Children,  .  26 
Thomas — Diet-Lists     and    Sick-Room 

Dietary, 28 

CHEMISTRY  AND  PHYSICS. 

Brockway — Essentials  of  Medical  Phys- 
ics,        7 

Wolff — Essentials  of  Medical  Chemistry,   29 

CHILDREN. 

An  American  Text-Book  of  Diseases 

of  Children,    .    .             3 

Griffith — Care  of  the  Baby, 12 

Griffith — Infant's  Weight  Chart,   ...  12 

Meigs — Feeding  in  Early  Infancy,    .    .  17 

Powell — Essentials  of  Dis.  of  Children,  19 

Starr — Diets  for  Infants  and  Children,  .  26 

DIAGNOSIS. 

Cohen  and  Eshner— Essentials  of  Di- 
agnosis,    9 

Corwin — Physical  Diagnosis,      ....      9 

Macdonald — Surgical  Diagnosis  and 
Treatment,      16 

Vierordt — Medical  Diagnosis,    ....    29 

DICTIONARIES. 

Borland — Pocket  I)ictionary,     ....  ID 

Keating— I'ronouncing  Dictionary,    .    .  14 

Morten — Nurse's  Dictionary,     ....  18 


EYE,  EAR,  NOSE,  AND  THROAT. 

An  American  Text- Book  of  Diseases 

of  the  Eye,  Ear,  Nose,  and  Throat,  .  3 
De  Schweinitz — Diseases  of  the  Eye, .  10 
Gleason — Essentials  of  Dis.  of  the  Ear,  1 1 
Jackson — Manual  of  Diseases  of  Eye,  .  32 
Jackson   and    Gleason — Essentials  of 

Diseases  of  the  Eye,  Nose,  and  Throat,  I4 
Kyle — Diseases  of  the  Nose  and  Throat,  15 

QENITO=URINARY. 

An  American  Text-Book  of  Genito- 
urinary and  Skin  Diseases, 4 

Hyde  and  Montgomery — Syphilis  and 
the  Venereal  Diseases,  ...         .    .    .    I3 

Martin — Essentials   of   Minor   Surgery, 

Bandaging,  and  Venereal  Diseases,  .  16 
Saundby — Renal  and  Urinary  Diseases,  24 
Senn — Genito-Urinary  Tuberculosis,  .  25 
Vecki — Sexual  Impotence, 28 

GYNECOLOGY. 

American  Text-Book  of  Gynecology,  4 
Cragin — Essentials  of  Gynecology,  .  .  9 
Garrigues — Diseases  of  Women,  ...  11 
Long — Syllabus  of  Gynecology,  ...  15 
Penrose — Diseases  of  Women,  ....  18 
Pryor — Pelvic  Inflammations,  ....  32 
Sutton  and  Giles— Diseases  of  Women,  28 

MATERIA  MEDICA,  PHARMACOL- 
OGY, AND  THERAPEUTICS. 

An  American  Text-Book  of  Applied 

Therapeutics, 3 

Butler — Text-Book  of  Materia  Medica, 

Therapeutics  and  Pharmacology,  ...  8 
Cerna — Notes  on  the  Newer  Remedies,  8 
Griffin — Materia  Med.  and  Therapeutics,  12 
Morris — Essentials  of    Materia   Medica 

and  Therapeutics, 17 

Saunders'  Pocket  Medical  Formulary,  24 
Sayre — Essentials  of  Pharmacy,  ...  24 
Stevens — Essentials  of  Materia  Medica 

and  Therapeutics, 26 

Stoney — Materia  Medica  for  Nurses,  .  .  28 
Thornton — Dose-Book  and  Manual  of 

Prescription-Writing, 28 

MEDICAL   JURISPRUDENCE    AND 
TOXICOLOGY. 

Chapman — Medical  Jurisprudence  and 
Toxicology,         ...  ....      8 

Semple — Essentials  of  Legal  Medicine, 
Toxicology,  and   Hygiene, 25 


Medical  Publications  of  W.  B.  Saunders. 


31 


NERVOUS  AND  MENTAL 
DISEASES,  ETC. 

Burr — Nervous  Diseases, 7 

Chapin — Compendium  of  Insanity,  .  .  8 
Church    and    Peterson — Nervous  and 

Mental  Diseases, 8 

Shaw — Essentials  of  Nervous  Diseases 

and  Insanity, 26 

NURSING. 

An  American  Text-Book  of  Nursing,  29 

Griffith — The  Care  of  the  Baby,    ...  12 

Hampton — Nursing, 12 

Hart — Diet  in  Sickness  and  in  Health,  13 

Meigs — Feeding  in  Early  Infancy,    .    .  17 

Morten — Nurse's  Dictionary,     ....  18 

Stoney— Materia  Medica  for  Nurses,  .    .  28 

Stoney — Practical  Points  in  Nursing,    .  27 

OBSTETRICS. 

An  Am  erican  Text-  Book  of  Obstetrics,  4 

Ashton — Essentials  of  Obstetrics,  ...  6 

Boisliniere — Obstetric  Accidents,  ...  7 

Dorland — Manual  of  Obstetrics,    .    .    .  lo 

Hirst — Text-Book  of  Obstetrics,  ...  13 
Norris — Syllabus  of  Obstetrics,  . ,  .    .    .18 

PATHOLOGY. 

An  American  Text-Book  of  Pathology,  5 
Mallory    and    ^A^^ight — Pathological 

Technique, 1 6 

Semple — Essentials    of    Pathology  and 

Morbid  Anatomy, 25 

Senn — Pathology  and  Surgical  Treat- 
ment of  Tumors, 25 

Stengel — Text- Book  of  Pathology,    .    .    26 
Warren — Surgical  Pathology  and  Thera- 
peutics,    29 

PHYSIOLOGY. 

An  American  Text-Book  of  Physi- 
ology, .  ■ . 5 

Hare — Essentials  of  Physiology,    ...  13 

Raymond — Manual  of  Physiology,   .    .  19 

Stewart — Manual  of  Physiology,  ...  27 

PRACTICE  OF  MEDICINE. 

An  American  Text-Book  of  the  The- 
ory and  Practice  of  Medicine,  ....      5 

An  American  Year-Book  of  Medicine 
and  Surgery,  6 

Anders — Text-Book  of  the  Practice  of 
Medicine, 6 

Lockwood — Manual  of  the  Practice  of 
Medicine, 15 

Morris — Essentials  of  the  Practice  of 
Medicine, 1 7 

Stevens — Manual  of  the  Practice  of 
Medicine, 27 

SKIN  AND  VENEREAL. 

An  American  Text-Book  of  Genito- 
urinary and  Skin  Diseases, 3 

Hyde  and  Montgomery — Syphilis  and 
the  Venereal  Diseases, 1 3 


Martin — Essentials  of  Minor  Surgery, 
Bandaging,  and  Venereal  Diseases,    .    16 

Pringle — Pictorial  Atlas  of  Skin  Dis- 
eases and  Syphilitic  Affections,    ...    19 

Stelwagon — Essentials  of  Diseases  of 
the  Skin, 26 

SURGERY. 

An  American  Text-Book  of  Surgery,     5 
An  American  Year-Book  of  Medicine 
and  Surgery 6 

Beck — Manual  of  Surgical  Asepsis,  .  .  7 
DaCosta — Manual  of  Surgery,  ....  10 
International  Text-Book  of  Surgery,  .    32 

Keen — Operation  Blank, 15 

Keen — The  Surgical  Complications  and 

Sequels  of  Typhoid  Fever, 15 

Macdonald — Surgical    Diagnosis    and 

Treatment,      16 

Martin — Essentials   of    Minor  Surgery, 

Bandaging,  and  Venereal  Diseases,     .    16 
Martin — Essentials  of  Surgery,  ....    16 

Moore — Orthopedic  Surgery, 17 

Nancrede — Principles  of  Surgery,  .  .  32 
Pye — Bandaging  and  Surgical  Dressing,  19 
Rowland    and    Hedley— Archives  of 

the  Roentgen  Ray, 19 

Senn — Genito-Urinary  Tuberculosis,      .    25 

Senn— Syllabus  of  Surgery, 25 

Senn — Pathology  and  Surgical  Treat- 
ment of  Tumors,    .         25 

Warren — Surgical  Pathology  and  Ther- 
apeutics,       29 

URINE  AND  URINARY  DISEASES. 

Saundby — Renal  and  Urinary  Diseases,  24 
Wolff— Essentials   of    Examination    of 
Urine, 29 

MISCELLANEOUS. 

Abbott — Hygiene  of  Transmissible  Dis- 
eases,   32 

Bastin — Laboratory  Exercises  in  Bot- 
any,      7 

Gould  and  Pyle — Anomalies  and  Curi- 
osities of  Medicine, 11 

Grafstrom^ — Massage,     .......     12 

Keating — How   to    Examine    loi°   Life 

Insurance, »    -    .    «      14 

Rowland    and    Hedley — Archives    of 

the  Roentgen  Ray, I9 

Saunders'  Medical  Hand-Atlases,  .  .  2 
Saunders'  New  Series  of  Manuals,  22,  23 
Saunders'  Pocket  Medical  Formulary,  .  24 
Saunders'  Question-Compends,  .  .  20,  21 
Senn — Pathology  and  Surgical  Treat- 
ment of  Tumors, -25 

Stewart  and  Lawrance — Essentials  of 

Medical  Electricity, 27 

Thornton — Dose-Book  and  Manual  of 

Prescription-Writing,    . 28 

Van  Valzah  and  Nisbet^Diseases  of 
the  Stomach, 28 


JUST  ISSUED, 


THE  INTERNATIONAL  TEXT=BOOK  OF  SURGERY.     In  two  volumes. 

By  Americaii  and  British  authors.  Edited  by  J.  Collins  Warren,  M.  D.,  LL.D., 
Professor  of  Surgery,  Harvard  Medical  School,  Boston ;  Surgeon  to  the  Massachusetts 
General  Hospital ;  and  A.  Pearce  Gould,  M.  S.,  F.  R.  C.  S.,  Eng.,  Lecturer  on 
Practical  Surgery  and  Teacher  of  Operative  Surgery,  Middlesex  Hospital  Medical 
School;  Surgeon  to  the  Middlesex  Hospital,  London,  England.  Vol.  L— General 
Surgery. — Handsome  octavo  volume  of  947  pages,  vi^ith  458  beautiful  illustrations  in 
the  text  and  9  lithographic  plates.  Vol.  H. — Special  or  Regional  Surgery — is  now  in 
press,  and  will  be  ready  Jan.  i,  1900.  Prices  per  volume:  Cloth,  ^5.00  net;  Half 
Morocco,  $6.00  net. 

KYLE  ON  THE  NOSE  AND  THROAT. 

Diseases  of  the  Nose  and  Throat.  By  D.  Braden  Kyle,  M.  D.,  Clinical  Pro- 
fessor of  Laryngology  and  Rhinology,  Jefferson  Medical  College,  Philadelphia;  Con- 
sulting Laryngologist,  Rhinologist,  and  Otologist,  St.  Agnes'  Hospital.  Octavo  volume 
of  646  pages,  with  over  150  illustrations  and  6  lithographic  plates.  Prices  :  Cloth,  $4.00 
net;    Half  Morocco,  ^5.00  net. 

PRYOR-PELVIC   INFLAMMATIONS. 

The  Treatment  of  Pelvic  Inflammations  through  the  Vagina.    By  W.  R. 

Pryor,  M.  D.,  Professor  of  Gynecology  in  the  New  York  Polyclinic.  i2mo  volume 
of  248  pages,  handsomely  illustrated.      Cloth,  ^2.00  net. 

ABBOTT  ON  TRANSMISSIBLE   DISEASES. 

The  Hygiene  of  Transmissible  Diseases :  their  Causation,  Modes  of 
Dissemination,  and  Methods  of  Prevention.  By  A.  C.  Abbott,  M.  D.,  Pro- 
fessor of  Hygiene  in  the  University  of  Pennsylvania  ;  Director  of  the  Laboratory  of 
Hygiene.  Octavo  volume  of  311  pages,  containing  a  number  of  charts  and  maps,  and 
numerous  illustrations.     Cloth,  ^2.00  net. 

HEISLER'S   EMBRYOLOGY. 

A  Text=Book  of  Embryology.  By  John  C.  Heisler,  M.D.,  Professor  of 
Anatomy  in  the  Medico-Chirurgical  College,  Philadelphia.  Octavo  volume  of  405 
pages,  with  190  illustrations,  26  in  colors.     Cloth,  ^2.50  net. 

JACKSON— DISEASES  OF  THE   EYE. 

A  Manual  of  Diseases  of  the  Eye.  By  Edward  Jackson,  A.  M.,  M.  D.,  some- 
lime  Professor  of  Diseases  of  the  Eye  in  the  Philadelphia  Polyclinic  and  College  for 
Graduates  in  Medicine.  l2mo  volume  of  over  535  pages,  with  178  beautiful  illustra- 
tions, mostly  from  drawings  by  the  author. 

NANCREDE -PRINCIPLES  OF    SURGERY. 

Lectures  on  the  Principles  of  Surgery.    By  Chas.  B.  Nancredk,  M.D.,  LL.D., 

Professor  of  Surgery  and  of  Clinical  Surgery,  University  of  Michigan,  Ann  Arbor. 
Octavo  volume  of   398  pages,  illustrated.      Cloth,  ^2.50  net. 

IN  PREPARATION  FOR  EARLY  PUBLICATION. 

OQDEN— URINARY    ANALYSIS. 

A  Manual  of  Urinary  Analysis,  hy  J.  Bkrcen  Ogden,  M.  D.,  Assistant  in 
Chemistry,  Harvard    University   Medical   School. 

STONEY— SURGICAL  TECHNIQUE  FOR  NURSES. 

Surgical  Technique  for  Nurses.  liy  Emily  A.  M.  Stonky,  Graduate  of  Training 
School  for  Nurses,  Lawrence,  Mass. ;  late  Superintendent  of  Training  School  for  Nurses, 
Carney   Hospital,  South   Boston,  Mass. 


